Masked cytokine polypeptides

ABSTRACT

Provided herein are cytokines or functional fragments thereof that, in some embodiments, are engineered to be masked by a masking moiety at one or more receptor binding site(s) of the cytokine or functional fragment thereof. In some embodiments, the cytokines are engineered to be activatable by a protease at a target site, such as in a tumor microenvironment, by including a proteolytically cleavable linker. In some embodiments, the proteolytically cleavable linker links the cytokine to the masking moiety, links the cytokine to a half-life extension domain, and/or links the masking moiety to a half-life extension domain. The masking moiety blocks, occludes, inhibits (e.g., decreases) or otherwise prevents (e.g., masks) the activity or binding of the cytokine to its cognate receptor or protein. Upon proteolytic cleavage of the cleavable linker at the target site, the cytokine becomes activated, which renders it capable of binding to its cognate receptor or protein with increased affinity.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.62/737,803, filed Sep. 27, 2018, U.S. Provisional Application No.62/888,276, filed Aug. 16, 2019, and U.S. Provisional Application No.62/891,199, filed Aug. 23, 2019. The contents of the above-listedapplications are incorporated herein by this reference in their entiretyfor all purposes.

INCORPORATION BY REFERENCE OF SEQUENCE LISTING

The present application is being filed along with a Sequence Listing inelectronic format. The Sequence Listing is provided as a file entitled737762000940SeqList, created Sep. 26, 2019, which is 1,024.111 KB insize. The information in the electronic format of the Sequence Listingis incorporated by reference in its entirety.

FIELD

This invention relates to masked cytokines and methods related to theuse and manufacture of the same.

BACKGROUND

Cancer is the second leading cause of death in the United States,accounting for more deaths than the next five leading causes (chronicrespiratory disease, stroke, accidents, Alzheimer's disease anddiabetes). While great strides have been made especially with targetedtherapies, there remains a great deal of work to do in this space.Immunotherapy and a branch of this field, immuno-oncology, is creatingviable and exciting therapeutic options for treating malignancies.Specifically, it is now recognized that one hallmark of cancer is immuneevasion and significant efforts have identified targets and developedtherapies to these targets to reactivate the immune system to recognizeand treat cancer.

Cytokine therapy is an effective strategy for stimulating the immunesystem to induce anti-tumor cytotoxicity. For example, aldesleukin, arecombinant form of interleukin-2 (IL-2), has been approved by the FDAfor the treatment of metastatic renal cell carcinoma and melanoma.Unfortunately, cytokines that are administered to patients generallyhave a very short half-life, thereby requiring frequent dosing. Forinstance, the product label of aldesleukin, marketed under the brandname Proleukin, states that the drug was shown to have a half-life of 85minutes in patients who received a 5-minute intravenous (IV) infusion.In addition, administration of high doses of cytokine can cause adversehealth outcomes, such as vascular leakage, through systemic immuneactivation. These findings illustrate the need for developing cytokinetherapeutics that effectively target tumors without the side effectsassociated with systemic immune activation. Provided herein are maskedcytokines, compositions thereof and methods of use thereof foraddressing this need.

All references cited herein, including patent applications, patentpublications, and scientific literature, are herein incorporated byreference in their entirety, as if each individual reference werespecifically and individually indicated to be incorporated by reference.

SUMMARY

The disclosed invention relates to the engineering and use of maskedcytokines or functional fragments thereof that, in some embodiments, areengineered to be masked by a masking moiety at one or more receptorbinding site(s) of the cytokine or functional fragment thereof. In someembodiments, the cytokines are engineered to be activatable by aprotease at a target site, such as in a tumor microenvironment, byincluding a proteolytically cleavable linker. In some embodiments, theproteolytically cleavable linker links the cytokine to the maskingmoiety, links the cytokine to a half-life extension domain, and/or linksthe masking moiety to a half-life extension domain. The masking moietyblocks, occludes, inhibits (e.g., decreases) or otherwise prevents(e.g., masks) the activity or binding of the cytokine to its cognatereceptor or protein. Upon proteolytic cleavage of the cleavable linkerat the target site, the cytokine becomes activated, which renders itcapable of binding to its cognate receptor or protein with increasedaffinity.

One embodiment comprises a masked cytokine comprising a masking moiety;and a cytokine or functional fragment thereof, wherein the maskingmoiety is linked to the cytokine or functional fragment thereof via alinker. In one aspect, the masked cytokine further comprises a half-lifeextension domain that is linked to either the masking moiety or thecytokine or functional fragment thereof.

In one embodiment, the masked cytokine comprises in an N to C-terminalor in a C to N-terminal direction: a) a masking moiety; b) a firstlinker; c) a cytokine or functional fragment thereof; and d) a half-lifeextension domain. In another embodiment, the masked cytokine comprisesin an N to C-terminal or in a C to N-terminal direction: a) a maskingmoiety; b) a first linker; c) a cytokine or functional fragment thereof;d) a second linker and e) a half-life extension domain. In anotherembodiment, the masked cytokine comprises in an N to C-terminal or in aC to N-terminal direction: a) a cytokine or functional fragment thereof;b) a first linker; c) a masking moiety; and d) a half-life extensiondomain.

In another embodiment, the masked cytokine comprises in an N toC-terminal or in a C to N-terminal direction: a) a cytokine orfunctional fragment thereof; b) a first linker; c) a masking moiety; d)a second linker; and e) a half-life extension domain.

In one embodiment, the cytokine or functional fragment thereof is anIL-2 polypeptide or functional fragment thereof or an IL-15 polypeptideor functional fragment thereof.

In one embodiment, the masked cytokine one or more amino acidsubstitutions into the amino acid sequence of the IL-2 or IL-15polypeptide or functional fragment thereof. In one embodiment, the aminoacid substitutions reduce the affinity of the IL-2 polypeptide orfunctional fragment thereof for CD25 (IL-2Rα).

In one embodiment, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by introducing one or moreamino acid substitutions into the amino acid sequence of the IL-2polypeptide or functional fragment thereof that increases the affinityof the IL-2 polypeptide or functional fragment thereof for IL-2R13 orIL-2Rγ.

In one embodiment, the half-life extension domain is an antibody orfragment thereof, and in some embodiments, one or more amino acidsubstitutions altering effector function.

In one embodiment, the antibody or fragment thereof is a Fragmentcrystallizable domain (Fc domain) or fragment thereof.

In one embodiment, the half-life extension domain is a polyamino acidsequence, such as a PAS polypeptide or an XTEN polypeptide.

In one embodiment the masked cytokine comprises a second masking moiety,wherein the second masking moiety is linked to the cytokine orfunctional fragment thereof via a second linker.

In one embodiment, the masked cytokine comprises in an N to C-terminalor in a C to N-terminal direction: a) a first masking moiety; b) a firstlinker; c) a cytokine or functional fragment thereof; d) a secondlinker; e) a second masking moiety; and f) a half-life extension domain.

In one embodiment, the masked cytokine comprises in an N to C-terminalor in a C to N-terminal direction: a) a first masking moiety; b) a firstlinker; c) a cytokine or functional fragment thereof; d) a secondlinker; e) a second masking moiety; f) a third linker; and g) ahalf-life extension domain.

In one embodiment, the masked cytokine comprises in an N to C-terminalor in a C to N-terminal direction: a) a second masking moiety; b) asecond linker; c) a cytokine or functional fragment thereof; d) a firstlinker; e) a first masking moiety; and f) a half-life extension domain.

In one embodiment, the masked cytokine comprises in an N to C-terminalor in a C to N-terminal direction: a) a second masking moiety; b) asecond linker; c) a cytokine or functional fragment thereof; d) a firstlinker; e) a first masking moiety; f) a third linker; and g) a half-lifeextension domain.

In one embodiment, the half-life extension domain is an albuminpolypeptide or functional fragment thereof.

In one embodiment, the cleavable peptide is cleaved by one or moreenzyme selected from the group consisting of: ABHD12, ADAM12, ABHD12B,ABHD13, ABHD17A, ADAM19, ADAM20, ADAM21, ADAM28, ADAM30, ADAM33, ADAMS,ABHD17A, ADAMDEC1, ADAMTS1, ADAMTS10, ADAMTS12, ADAMTS13, ADAMTS14,ADAMTS15, ADAMTS16, ADAMTS17, ADAMTS18, ADAMTS19, ADAMTS2, ADAMTS20,ADAMTS3, ADAMTS4, ABHD17B, ADAMTS5, ADAMTS6, ADAMTS7, ADAMTS8, ADAMTS9,ADAMTSL1, ADAMTSL2, ADAMTSL3, ABHD17C, ADAMTSL5, ASTL, BMP1, CELA1,CELA2A, CELA2B, CELA3A, CELA3B, ADAM10, ADAM15, ADAM17, ADAMS, ADAMTS4,CTSE, CTSF, ADAMTSL4, CMA1, CTRB1, CTRC, CTSO, CTR1, CTSA, CTSW, CTSB,CTSC, CTSD, ESP1, CTSG, CTSH, GZMA, GZMB, GZMH, CTSK, GZMM, CTSL, CTSS,CTSV, CTSZ, HTRA4, KLK10, KLK11, KLK13, KLK14, KLK2, KLK4, DPP4, KLK6,KLK7, KLKB1, ECE1, ECE2, ECEL1, MASP2, MEP1A, MEP1B, ELANE, FAP, GZMA,MMP11, GZMK, HGFAC, HPN, HTRA1, MMP11, MMP16, MMP17, MMP19, HTRA2,MMP20, MMP21, HTRA3, HTRA4, KEL, MMP23B, MMP24, MMP25, MMP26, MMP27,MMP28, KLK5, MMP3, MMP1, MMP8, MMP9, LGMN, LNPEP, MASP1, PAPPA, PAPPA2,PCSK1, NAPSA, PCSK5, PCSK6, MME, MMP1, MMP10, PLAT, PLAU, PLG, PRSS1,PRSS12, PRSS2, PRSS21, PRSS3, PRSS33, PRSS4, PRSS55, PRSS57, MMP12,PRSS8, PRSS9, PRTN3, MMP13, MMP14, ST14, TMPRSS10, TMPRSS11A, TMPRSS11D,TMPRSS11E, TMPRSS11F, TMPRSS12, TMPRSS13, MMP15, TMPRSS15, MMP2,TMPRSS2, TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS6, TMPRSS7, TMPRSS9, NRDC,OVCH1, PAMR1, PCSK3, PHEX, TINAG, TPSAB1, TPSD1, and TPSG1.

In one embodiment, the half-life extension domain is conjugated to anagent, such as an inhibitor of tubulin polymerization, a DNA damagingagent, or a DNA synthesis inhibitor, a maytansinoid, an auristatin, apyrrolobenzodiazepine (PBD) dimer, a calicheamicin, a duocarmycin, aindo-linobenzodiazepine dimer or exatecan derivative Dxd.

In one embodiment, the half-life extension domain is conjugated to animmune stimulant, such as a stimulator of interferon genes (STING)agonist, such as a cyclic dinucleotide (CDN), such as cGAMP, c-di-AMP,c-di-GMP, cAIMP, c-di-IMP, or4-(2-chloro-6-fluorobenzyl)-N-(furan-2-ylmethyl)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamideor a toll-like receptor (TLR) agonist, such as TLR1, TLR2, TLR3, TLR4,TLR5, TLR6, TLR7, TLR8, TLR9, or TLR10.

In one embodiment, the masked cytokine comprises a first half-lifeextension domain and a second half-life extension domain, wherein themasking moiety is linked to the first half-life extension domain, andwherein the cytokine or functional fragment thereof is linked to thesecond half-life extension domain,

In one embodiment, the first half-life extension domain and the secondhalf-life extension domain contain modifications promoting theassociation of the first and the second half-life extension domain.

One embodiment comprises a nucleic acid encoding the masked cytokinesdescribed herein. Another embodiment encompasses a vector comprising thenucleic acid. In another embodiment a host cell comprising the nucleicacid. Another embodiment comprises one or more nucleic acids encodingthe masked cytokines described herein. Another embodiment encompasses avector comprising the one or more nucleic acids. Another embodimentencompasses one or more vectors comprising the one or more nucleicacids.

In another embodiment is provided a method of producing a maskedcytokine comprising culturing the host cell under a condition thatproduces the masked cytokine. In one embodiment, the masked cytokineproduced by the host cell is recovered. One embodiment encompasses amasked cytokine produced by the disclosed methods.

In one embodiment, a composition comprising a disclosed masked cytokineis provided. In another embodiment, the composition further comprises ananti-inflammatory agent or an anti-cancer agent, such as a PD-1inhibitor, an EGFR inhibitor, a HER2 inhibitor, a VEGFR inhibitor, aCTLA-4 inhibitor, a BTLA inhibitor, a B7H4 inhibitor, a B7H3 inhibitor,a CSFIR inhibitor, an HVEM inhibitor, a CD27 inhibitor, a KIR inhibitor,an NKG2A inhibitor, an NKG2D agonist, a TWEAK inhibitor, an ALKinhibitor, a CD52 targeting antibody, a CCR4 targeting antibody, a PD-L1inhibitor, a KIT inhibitor, a PDGFR inhibitor, a BAFF inhibitor, an HDACinhibitor, a VEGF ligand inhibitor, a CD19 targeting molecule, a FOLR1targeting molecule, a DLL3 targeting molecule, a DKK1 targetingmolecule, a MUC1 targeting molecule, a MUC16 targeting molecule, a PSMAtargeting molecule, an MSLN targeting molecule, an NY-ESO-1 targetingmolecule, a B7H3 targeting molecule, a B7H4 targeting molecule, a BCMAtargeting molecule, a CD29 targeting molecule, a CD151targetingmolecule, a CD123 targeting molecule, a CD33 targeting molecule, a CD37targeting molecule, a CDH19 targeting molecule, a CEA targetingmolecule, a Claudin 18.2 targeting molecule, a CLEC12A targetingmolecule, an EGFRVIII targeting molecule, an EPCAM targeting molecule,an EPHA2 targeting molecule, an FCRH5 targeting molecule, an FLT3targeting molecule, a GD2 targeting molecule, a glypican 3 targetingmolecule, a gpA33 targeting molecule, a GPRC5D targeting molecule, anIL-23R targeting molecule, an IL-1RAP targeting molecule, a MCSPtargeting molecule, a RON targeting molecule, a ROR1 targeting molecule,a STEAP2 targeting molecule, a TfR targeting molecule, a CD166 targetingmolecule, a TPBG targeting molecule, a TROP2 targeting molecule, aproteasome inhibitor, an ABL inhibitor, a CD30 inhibitor, a FLT3inhibitor, a MET inhibitor, a RET inhibitor, an IL-113 inhibitor, a MEKinhibitor, a ROS1 inhibitor, a BRAF inhibitor, a CD38 inhibitor, a RANKLinhibitor, a B4GALNT1 inhibitor, a SLAMF7 inhibitor, an IDH2 inhibitor,an mTOR inhibitor, a CD20 targeting antibody, a BTK inhibitor, a PI3Kinhibitor, a FLT3 inhibitor, a PARP inhibitor, a CDK4 inhibitor, a CDK6inhibitor, an FGFR inhibitor, a RAF inhibitor, a JAK1 inhibitor, a JAK2inhibitor, a JAK3 inhibitor, an IL-6 inhibitor, a IL-17 inhibitor, aSmoothened inhibitor, an IL-6R inhibitor, a BCL2 inhibitor, a PTCHinhibitor, a PIGF inhibitor, a TGFB inhibitor, a CD28 agonist, a CD3agonist, CD40 agonist, a GITR agonist, a OX40 agonist, a VISTA agonist,a CD137 agonist, a LAG3 inhibitor, a TIM3 inhibitor, a TIGIT inhibitor,or an IL-2R inhibitor.

In one embodiment, the anti-inflammatory agent is a cyclooxygenase (COX)inhibitor, such as a COX-1 and/or COX-2 inhibitor, such as SC-560,FR122047, P6, mofezolac, TFAP, flurbiprofen, ketoprofen, celecoxib,rofecoxib, meloxicam, piroxicam, deracoxib, parecoxib, valdecoxib,etoricoxib, a chromene derivative, a chroman derivative,N-(2-cyclohexyloxynitrophenyl) methane sulfonamide, parecoxib,lumiracoxib, RS 57067, T-614, BMS-347070, JTE-522, S-2474, SVT-2016,CT-3, ABT-963, SC-58125, nimesulide, flosulide, NS-398, L-745337,RWJ-63556, L-784512, darbufelone, CS-502, LAS-34475, LAS-34555, S-33516,diclofenac, mefenamic acid, SD-8381, ibuprofen, naproxen, ketorolac,indomethacin, aspirin, naproxen, tolmetin, piroxicam, or meclofenamate.

In one embodiment, the anti-inflammatory agent is an NF-κB inhibitor,such as an IKK complex inhibitor, an IκB degradation inhibitor, an NF-κBnuclear translocation inhibitor, a p65 acetylation inhibitor, an NF-κBDNA binding inhibitor, an NF-κB transactivation inhibitor, or a p53induction inhibitor.

In one embodiment, the NF-κB inhibitor is TPCA-1, NF-κB ActivationInhibitor VI (BOT-64), BMS-345541, amlexanox, SC-514 (GK-01140),IMD-0354, IKK-16, BAY-11-7082, MG-115, MG-132, lactacystin, epoxomicin,parthenolide, carfilzomib, MLN-4924 (pevonedistat), JSH-23 rolipram,gallic acid, anacardic acid, GYY-4137, p-XSC, CV-3988, prostaglandin E2(PGE2), LY-294002, wortmannin, mesalamine, quinacrine, or flavopiridol.

One embodiment encompasses a pharmaceutical composition comprising adisclosed masked cytokine and a pharmaceutically acceptable carrier.

Another embodiment encompasses a kit comprising the disclosed maskedcytokine.

Another embodiment comprises a method of treating or preventing aneoplastic disease in a subject, the method comprising administering tothe subject an effective amount of a disclosed masked cytokinecomposition for the treatment of a disease or condition, such as aneoplastic disease, for example, cancer. In one embodiment the cancer isleukemia, lymphoma, head and neck cancer, colorectal cancer, prostatecancer, pancreatic cancer, melanoma, breast cancer, neuroblastoma, lungcancer, ovarian cancer, bone cancer (e.g., osteosarcoma, chondrosarcoma,Ewing sarcoma), bladder cancer, cervical cancer, liver cancer, kidneycancer, skin cancer, testicular cancer, adrenal cancer, adenoid cysticcarcinoma, anal cancer, brain cancer, ductal carcinoma, endometrialcancer, esophageal cancer, gastric cancer, oral cancer, thyroid cancer,retinoblastoma, parathyroid cancer, pituitary cancer, bile duct cancer,or uterine cancer. In some embodiments, the cancer is selected from thegroup consisting of lymphoma, sarcoma, bladder cancer, bone cancer,brain tumor, cervical cancer, colon cancer, esophageal cancer, gastriccancer, head and neck cancer, kidney cancer, myeloma, thyroid cancer,leukemia, prostate cancer, breast cancer (e.g. triple negative, ERpositive, ER negative, chemotherapy resistant, Herceptin resistant, HER2positive, doxorubicin resistant, tamoxifen resistant, ductal carcinoma,lobular carcinoma, primary, metastatic), ovarian cancer, pancreaticcancer, liver cancer (e.g. hepatocellular carcinoma), lung cancer (e.g.non-small cell lung carcinoma, squamous cell lung carcinoma,adenocarcinoma, large cell lung carcinoma, small cell lung carcinoma,carcinoid, sarcoma), glioblastoma multiforme, glioma, melanoma, prostatecancer, castration-resistant prostate cancer, breast cancer, triplenegative breast cancer, glioblastoma, ovarian cancer, lung cancer,squamous cell carcinoma (e.g., head, neck, or esophagus), colorectalcancer, leukemia, acute myeloid leukemia, lymphoma, B cell lymphoma, ormultiple myeloma. Additional examples include, cancer of the thyroid,endocrine system, brain, breast, cervix, colon, head & neck, esophagus,liver, kidney, lung, non-small cell lung, melanoma, mesothelioma, ovary,sarcoma, stomach, uterus or Medulloblastoma, Hodgkin's Disease,Non-Hodgkin's Lymphoma, multiple myeloma, neuroblastoma, glioma,glioblastoma multiforme, ovarian cancer, rhabdomyosarcoma, primarythrombocytosis, primary macroglobulinemia, primary brain tumors, cancer,malignant pancreatic insulanoma, malignant carcinoid, urinary bladdercancer, premalignant skin lesions, testicular cancer, lymphomas, thyroidcancer, neuroblastoma, esophageal cancer, genitourinary tract cancer,malignant hypercalcemia, endometrial cancer, adrenal cortical cancer,neoplasms of the endocrine or exocrine pancreas, medullary thyroidcancer, medullary thyroid carcinoma, melanoma, colorectal cancer,papillary thyroid cancer, hepatocellular carcinoma, Paget's Disease ofthe Nipple, Phyllodes Tumors, Lobular Carcinoma, Ductal Carcinoma,cancer of the pancreatic stellate cells, cancer of the hepatic stellatecells, or prostate cancer.

Another embodiment comprises a method of treating or preventing aninflammatory or autoimmune disease in a subject, the method comprisingadministering to the subject an effective amount of a disclosed maskedcytokine composition, wherein the inflammatory or autoimmune disease isselected from the group consisting of atherosclerosis, obesity,inflammatory bowel disease (IBD), rheumatoid arthritis, allergicencephalitis, psoriasis, atopic skin disease, osteoporosis, peritonitis,hepatitis, lupus, celiac disease, Sjogren's syndrome, polymyalgiarheumatica, multiple sclerosis (MS), ankylosing spondylitis, type 1diabetes mellitus, alopecia areata, vasculitis, and temporal arteritis,graft versus host disease (GVHD), asthma, COPD, a paraneoplasticautoimmune disease, cartilage inflammation, juvenile arthritis, juvenilerheumatoid arthritis, pauciarticular juvenile rheumatoid arthritis,polyarticular juvenile rheumatoid arthritis, systemic onset juvenilerheumatoid arthritis, juvenile ankylosing spondylitis, juvenileenteropathic arthritis, juvenile reactive arthritis, juvenile Reiter'sSyndrome, SEA Syndrome (Seronegativity, Enthesopathy, ArthropathySyndrome), juvenile dermatomyositis, juvenile psoriatic arthritis,juvenile Scleroderma, juvenile systemic lupus erythematosus, juvenilevasculitis, pauciarticular rheumatoid arthritis, systemic onsetrheumatoid arthritis, enteropathic arthritis, reactive arthritis,Reiter's Syndrome, dermatomyositis, psoriatic arthritis, Scleroderma,vasculitis, myolitis, polymyolitis, dermatomyolitis, polyarteritisnodossa, Wegener's granulomatosis, arteritis, ploymyalgia rheumatica,sarcoidosis, Sclerosis, primary biliary Sclerosis, Sclerosingcholangitis, psoriasis, plaque psoriasis, guttate psoriasis, inversepsoriasis, pustular psoriasis, erythrodermic psoriasis, dermatitis,atopic dermatitis, atherosclerosis, Still's disease, Systemic LupusErythematosus (SLE), myasthenia gravis, Crohn's disease, ulcerativecolitis, celiac disease, rhinosinusitis, rhinosinusitis with polyps,eosinophilic esophogitis, eosinophilic bronchitis, Guillain-Barredisease, thyroiditis (e.g., Graves' disease), Addison's disease,Raynaud's phenomenon, autoimmune hepatitis, transplantation rejection,kidney damage, hepatitis C-induced vasculitis, or spontaneous loss ofpregnancy.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A and FIG. 1B show the structure of exemplary embodiments of amasked cytokine that includes a masking moiety, a cytokine or functionalfragment thereof (“cytokine”), a half-life extension domain, and a firstlinker that includes a first cleavable peptide (“1CP”), a firstN-terminal spacer domain (“1NSD”), and a first C-terminal spacer domain(“1CSD”). These exemplary embodiments also include a second linker thatincludes a second cleavable peptide (“2CP”), a second N-terminal spacerdomain (“2NSD”), and a second C-terminal spacer domain (“2CSD”). Asshown by the arrows, while the exemplary embodiments shows the maskingmoiety linked to the first linker, and the cytokine or functionalfragment thereof is linked to the first linker and the second linker,the masking moiety and the cytokine or functional fragment thereof canbe interchanged such that the cytokine or functional fragment thereof islinked to the first linker, and the masking moiety is linked to thefirst linker and the second linker. FIG. 1A shows the structure of anexemplary embodiment of a masked cytokine as a monomer. FIG. 1B showsthe structure of an exemplary embodiment of a masked cytokine as ahomodimer formed by disulfide bonds.

FIG. 2A and FIG. 2B show the structure of exemplary embodiments of amasked cytokine that includes a first masking moiety (“Mask 1”), acytokine or functional fragment thereof (“cytokine”), a second maskingmoiety (“Mask 2”), a half-life extension domain, a first linker thatincludes a first cleavable peptide (“1CP”), a first N-terminal spacerdomain (“1NSD”), and a first C-terminal spacer domain (“1CSD”), and asecond linker that includes a second cleavable peptide (“2CP”), a secondN-terminal spacer domain (“2NSD”), and a second C-terminal spacer domain(“2CSD”). These exemplary embodiments also include a third linker thatincludes a third cleavable peptide (“3CP”), a third N-terminal spacerdomain (“3NSD”), and a third C-terminal spacer domain (“3CSD”). FIG. 2Ashows the structure of an exemplary embodiment of a masked cytokine as amonomer. FIG. 2B shows the structure of an exemplary embodiment of amasked cytokine as a homodimer formed by disulfide bonds.

FIG. 3A shows the structure of an exemplary embodiment of a maskedcytokine that includes a masking moiety, a cytokine or functionalfragment thereof (“cytokine”), a first half-life extension domain, and asecond half-life extension domain. The exemplary embodiment shown inFIG. 3A also includes a first linker that includes a first cleavablepeptide (“1CP”), a first N-terminal spacer domain (“1NSD”), and a firstC-terminal spacer domain (“1CSD”), and a second linker that includes asecond cleavable peptide (“2CP”), a second N-terminal spacer domain(“2NSD”), and a second C-terminal spacer domain (“2CSD”). The exemplaryfirst and second half-life extension domains include “knobs into holes”modifications that promote the association of the first half-lifeextension domain with the second half-life extension domain, as shown bythe “hole” in the first half-life extension domain and the “knob” in thesecond half-life extension domain. The first half-life extension domainand the second half-life extension domain are also shown as associating,at least in part, due to the formation of disulfide bonds. It is to beunderstood that although the “hole” is depicted as part of the firsthalf-life extension domain (linked to the masking moiety) and the “knob”is depicted as part of the second half-life extension domain (linked tothe cytokine), the “hole” and the “knob” can alternatively be includedin the second half-life extension domain and the first half-lifeextension domain, respectively, so that the “hole” is a part of thesecond half-life extension domain (linked to the cytokine) and the“knob” is part of the first half-life extension domain (linked tomasking moiety). FIG. 3B shows the structure of an exemplary embodimentof a masked cytokine that includes a masking moiety, a cytokine orfunctional fragment thereof (“cytokine”), a first half-life extensiondomain, a second half-life extension domain, and a third linker thatincludes a third N-terminal spacer domain (“3NSD”) and a thirdC-terminal spacer domain (“3CSD”). The third linker links the firsthalf-life extension domain to the second half-life extension domain. Theexemplary embodiment shown in FIG. 3B also includes a first linker thatincludes a first cleavable peptide (“1CP”), a first N-terminal spacerdomain (“1NSD”), and a first C-terminal spacer domain (“1CSD”), and asecond linker that includes a second cleavable peptide (“2CP”), a secondN-terminal spacer domain (“2NSD”), and a second C-terminal spacer domain(“2CSD”).

FIG. 4 shows a dimer of the exemplary masked cytokine shown in FIG. 3Aformed by disulfide bonds.

FIG. 5A shows the structure of an exemplary embodiment of a maskedcytokine that includes a first masking moiety (“Mask 1”), a firsthalf-life extension domain, a second masking moiety (“Mask 2”), acytokine or functional fragment thereof (“cytokine”), and a secondhalf-life extension domain. The exemplary embodiment shown in FIG. 5Aalso includes a first linker that includes a first cleavable peptide(“1CP”), a first N-terminal spacer domain (“1NSD”), and a firstC-terminal spacer domain (“1CSD”), a second linker that includes asecond cleavable peptide (“2CP”), a second N-terminal spacer domain(“2NSD”), and a second C-terminal spacer domain (“2CSD”), and a thirdlinker that includes a third cleavable peptide (“3CP”), a thirdN-terminal spacer domain (“3NSD”), and a third C-terminal spacer domain(“3CSD”). It is to be understood that although the “hole” is depicted aspart of the first half-life extension domain (linked to the maskingmoiety) and the “knob” is depicted as part of the second half-lifeextension domain (linked to the cytokine), the “hole” and the “knob” canalternatively be included in the second half-life extension domain andthe first half-life extension domain, respectively, so that the “hole”is a part of the second half-life extension domain (linked to thecytokine) and the “knob” is part of the first half-life extension domain(linked to masking moiety). FIG. 5B shows the structure of an exemplaryembodiment of a masked cytokine that includes a first masking moiety(“Mask 1”), a first half-life extension domain, a second masking moiety(“Mask 2”), a cytokine or functional fragment thereof (“cytokine”), asecond half-life extension domain, and a fourth linker that includes afourth N-terminal spacer domain (“4NSD”) and a fourth C-terminal spacerdomain (“4CSD”). The fourth linker links the first half-life extensiondomain to the second half-life extension domain. The exemplaryembodiment shown in FIG. 5B also includes a first linker that includes afirst cleavable peptide (“1CP”), a first N-terminal spacer domain(“1NSD”), and a first C-terminal spacer domain (“1CSD”), a second linkerthat includes a second cleavable peptide (“2CP”), a second N-terminalspacer domain (“2NSD”), and a second C-terminal spacer domain (“2CSD”),and a third linker that includes a third cleavable peptide (“3CP”), athird N-terminal spacer domain (“3NSD”), and a third C-terminal spacerdomain (“3CSD”). As shown by the arrows in FIGS. 5A and 5B, while theexemplary embodiment shows the second masking moiety linked to the thirdlinker, and the cytokine or functional fragment thereof is linked to thethird linker and the second linker, the first masking moiety and thecytokine or functional fragment thereof can be interchanged such thatthe cytokine or functional fragment thereof is linked to the thirdlinker, and the first masking moiety is linked to the third linker andthe second linker.

FIG. 6 shows a dimer of the exemplary masked cytokine shown in FIG. 5Aformed by disulfide bonds.

FIGS. 7A-7E shows exemplary embodiments of masked cytokines prior to(left) and after (right) cleavage by a protease, such as at the tumormicroenvironment. FIGS. 7A-7D show exemplary embodiments of a maskedIL-2 cytokine, and FIG. 7E shows an exemplary embodiment of a maskedIL-15 cytokine. Cleavage by a protease releases a masking moiety (e.g.,IL-2Rβ, as shown in FIGS. 7A, 7B, and 7D), or releases an IL-2 (FIG.7C), or releases IL-15 (FIG. 7E).

FIG. 8 shows SDS-PAGE analysis on flow-through (FT) samples (i.e.,proteins that did not bind to the Protein A column) and the eluted (E)samples (i.e., proteins that bound to the Protein A column and wereeluted from it) following production and purification of exemplaryconstructs (AK304, AK305, AK307, AK308, AK309, AK310, AK311, AK312,AK313, AK314, and AK315).

FIGS. 9A-9D shows results from SPR analysis that tested the binding ofexemplary masked IL-2 polypeptide constructs (AK215 and AK216), or arhIL2 control, to CD25-Fc. FIG. 9A shows the interaction between AK215and CD25-Fc, FIG. 9B shows the interaction between AK216 and CD25-Fc,and FIG. 9C shows the interaction between a recombinant human IL2(rhIL2) control and CD25-Fc.

FIG. 9D provides a table summarizing the data obtained for theassociation constant (ka), dissociation constant (kd), equilibriumdissociation constant (KD), as well as the Chi² value and U-value foreach interaction.

FIGS. 10A-10D shows results from SPR analysis that tested the binding ofexemplary masked IL-2 polypeptide constructs (AK216 and AK218), or arhIL2 control, to CD122-Fc. FIG. 10A shows the interaction between AK216and CD122-Fc, FIG. 10B shows the interaction between AK218 and CD122-Fc,and FIG. 10C shows the interaction between a recombinant human IL2(rhIL2) control and CD122-Fc. FIG. 10D provides a table summarizing thedata obtained for the association constant (ka), dissociation constant(kd), equilibrium dissociation constant (KD), as well as the Chi^(t)value and U-value for each interaction.

FIG. 11A shows an exemplary embodiment of a masked cytokines prior to(left) and after (right) cleavage by a protease, such as at the tumormicroenvironment. FIG. 11B shows SDS-PAGE analysis of an exemplarymasked IL-2 polypeptide construct that was incubated in the absence(left lane) or presence (right lane) of the MMP10 protease, whichdemonstrates the release of IL-2 from the Fc portion.

FIGS. 12A-12D shows STAT5 activation (%) in PBMCs treated with theconstruct AK032, AK035, AK041, or rhIL-2 as a control. The levels ofSTAT5 activation (%) are shown for NK cells, CD8+ T cells, effector Tcells (Teff), and regulatory T cells (Treg), as determined followingincubation with rhIL-2 (FIG. 12A), AK032 (FIG. 12B), AK035 (FIG. 12C),or AK041 (FIG. 12D).

FIGS. 13A-13C shows STAT5 activation (%) in PBMCs treated with theconstruct AK081 or AK032. The AK081 construct with and without priorexposure to MMP10 was tested. An isotype control as well as a no IL-2negative control was also tested. The levels of STAT5 activation (%) areshown for NK cells (FIG. 13A), CD8+ T cells (FIG. 13C), and CD4+ T cells(FIG. 13B).

FIGS. 14A-14D shows the results from STAT5 activation studies in PBMCsusing constructs AK081 and AK111, as well as controls that included anrhIL-2 and anti-RSV antibody. A no-treatment control was also tested.EC50 (pM) is also shown for the rhIL-2, AK081, and AK111 treatments.STAT5 activation (%) is shown for CD4+FoxP3+CD25+ cells (FIG. 14A), CD8+cells (FIG. 14B), and CD4+FoxP3-CD25− cells (FIG. 14C). FIG. 14Dprovides EC50 (pM) and fold-change data for the AK081, AK111 constructs,as well as the rhIL-2 control.

FIGS. 15A-15D shows the results from STAT5 activation studies in PBMCsusing constructs AK167 and AK168, as well as controls that included anrhIL-2 and anti-RSV antibody. A no-treatment control was also tested.EC50 (pM) is also shown for the rhIL-2, AK167, and AK168 treatments.STAT5 activation (%) is shown for CD4+FoxP3+CD25+ cells (FIG. 15A), CD8+cells (FIG. 15B), and CD4+FoxP3-CD25− cells (FIG. 15C). FIG. 15Dprovides EC50 (pM) and fold-change data for the AK167 and AK168constructs, as well as the rhIL-2 control.

FIGS. 16A-16D shows STAT5 activation (%) in PBMCs treated with theconstruct AK165 or AK166, or an isotype control or an IL-2-Fc control,that were (+MMP10) or were not previously exposed to the MMP10 protease.The key as shown in FIG. 16A also applies to FIG. 16B, and the key asshown in FIG. 16C also applies to FIG. 16D. STAT5 activation (%) isshown for CD4+FoxP3+T regulatory cells (FIG. 16A), CD4+FoxP3− T helpercells (FIG. 16B), CD8+cytotoxic T cells (FIG. 16C), and CD56+NK cells(FIG. 16D).

FIGS. 17A-17C shows STAT5 activation (%) in PBMCs treated with theconstruct AK109 or AK110, or an isotype control or an IL-2-Fc control,that were (+MMP10) or were not previously exposed to the MMP10 protease.The key as shown in FIG. 17B also applies to FIG. 17A. STAT5 activation(%) is shown for NK cells (FIG. 17A), CD8 cells (FIG. 17B), and CD4cells (FIG. 17C).

FIGS. 18A-18D shows the results from STAT5 activation studies in PBMCsusing the constructs AK211, AK235, AK253, AK306, AK310, AK314, andAK316, as well as an an rhIL-2 control. STAT5 activation (%) is shownfor CD3+CD4+FoxP3+ cells (FIG. 18A), CD3+CD4+FoxP3-cells (FIG. 18B), andCD3+CD8+ cells (FIG. 18C). FIG. 18D provides EC50 data for each of thetested constructs as well as the rhIL-2 control.

FIGS. 19A-19D shows the results from STAT5 activation studies in PBMCsusing the constructs AK081, AK167, AK216, AK218, AK219, AK220, and AK223that have been activated by protease, as well as an an rhIL-2 control.STAT5 activation (%) is shown for CD4+FoxP3+CD25+ regulatory T cells(FIG. 19A), CD4+FoxP3-CD25− cells (FIG. 19B), and CD8+ cells (FIG. 19C).FIG. 19D provides EC50 data for each of the tested constructs as well asthe rhIL-2 control.

FIGS. 20A-20C shows STAT5 activation (%) in PBMCs treated with theconstruct AK081, AK189, AK190, or AK210, or an anti-RSV control. The keyas shown in FIG. 20A also applies to FIGS. 20B and 20C. STAT5 activation(%) is shown for regulatory T cells (FIG. 20A), CD4 helper T cells (FIG.20B), and CD8 cells (FIG. 20C).

FIGS. 21A-21C shows STAT5 activation (%) in PBMCs treated with theconstruct AK167, AK191, AK192, or AK193, or an anti-RSV control. The keyas shown in FIG. 21A also applies to FIGS. 21B and 21C. STAT5 activation(%) is shown for regulatory T cells (FIG. 21A), CD4 helper T cells (FIG.21B), and CD8 cells (FIG. 21C).

FIGS. 22A and 22B show the results from reporter bioassays on anexemplary masked IL-15 polypeptide construct, AK248, with (+MMP) orwithout prior exposure to an activating protease, or a rhIL-15 as acontrol. FIG. 22A shows results from a reporter bioassay using aHEK-Blue IL2 reporter cell line, and FIG. 22B shows results from areporter bioassay using an IL-15 bioassay with a mouse CTLL2 cell line.

FIGS. 23A-23D show results from pharmacokinetic studies carried out intumor-bearing mice using the construct AK032, AK081, AK111, AK167, orAK168, or an anti-RSV control. FIG. 23A provides a simplistic depictionof the structure of each of the constucts tested. FIG. 23B shows Fclevels in plasma (μg/mL) by detecting human IgG, FIG. 23C shows Fc-CD122levels in plasma (μg/mL) by detecting human CD122, and FIG. 23D showsFc-IL2 levels in plasma (μg/mL) by detecting human IL-2. Prior to thedetection step, an anti-human IG was used as the capture antibody.

FIGS. 24A-24D show results from pharmacokinetic studies carried out intumor-bearing mice using the construct AK167, AK191 AK197, AK203, AK209,or AK211, or an anti-RSV control. FIG. 24A provides a simplisticdepiction of the structure of each of the constucts tested. FIG. 24Bshows Fc levels in plasma (μg/mL) by detecting human IgG, FIG. 24C showsFc-IL2 levels in plasma (μg/mL) by detecting human IL-2, and FIG. 24Dshows Fc-CD122 levels in plasma (μg/mL) by detecting human CD122. Priorto the detection step, an anti-human IG was used as the captureantibody.

FIGS. 25A-25L shows results from studies testing the in vivo responsesof CD4, CD8, NK, and Treg percentages in spleen, blood, and tumor, usingthe AK032, AK081, AK111, AK167, or AK168 construct, or an anti-RSV IgGcontrol. For spleen tissue, % CD8 cells of CD3 cells (FIG. 25A), % CD4of CD3 cells (FIG. 25B), % NK cells of CD3− cells (FIG. 25C), % FoxP3 ofCD4 cells (FIG. 25D) is shown. For blood, % CD8 cells of CD3 cells (FIG.25E), % CD4 of CD3 cells (FIG. 25F), % NK cells of CD3− cells (FIG.25G), % FoxP3 of CD4 cells (FIG. 25H) is shown. For tumor tissue, % CD8cells of CD3 cells (FIG. 25I), % CD4 of CD3 cells (FIG. 25J), % NK cellsof CD3− cells (FIG. 25K), % FoxP3 of CD4 cells (FIG. 25L) is shown.

FIGS. 26A-26L shows results from studies testing the in vivo responsesof CD4, CD8, NK, and Treg percentages in spleen, blood, and tumor, usingthe AK167, AK168, AK191, AK197, AK203, AK209, or AK211 construct, or ananti-RSV IgG control. For spleen tissue, % CD8 cells of CD3 cells (FIG.26A), % CD4 of CD3 cells (FIG. 26B), % NK cells of CD3− cells (FIG.26C), % FoxP3 of CD4 cells (FIG. 26D) is shown. For blood, % CD8 cellsof CD3 cells (FIG. 26E), % CD4 of CD3 cells (FIG. 26F), % NK cells ofCD3− cells (FIG. 26G), % FoxP3 of CD4 cells (FIG. 26H) is shown. Fortumor tissue, % CD8 cells of CD3 cells (FIG. 26I), % CD4 of CD3 cells(FIG. 26J), % NK cells of CD3− cells (FIG. 26K), % FoxP3 of CD4 cells(FIG. 26L) is shown.

FIGS. 27A-27L shows results from studies testing the in vivo responsesof CD4, CD8, NK, and Treg percentages in spleen, blood, and tumor, usingthe AK235, AK191, AK192, AK193, AK210, AK189, AK190, or AK211 construct,or an anti-RSV IgG control. For spleen tissue, % CD8 cells of CD3 cells(FIG. 27A), % CD4 of CD3 cells (FIG. 27B), % NK cells of CD3− cells(FIG. 27C), % FoxP3 of CD4 cells (FIG. 27D) is shown. For blood, % CD8cells of CD3 cells (FIG. 27E), % CD4 of CD3 cells (FIG. 27F), % NK cellsof CD3− cells (FIG. 27G), % FoxP3 of CD4 cells (FIG. 27H) is shown. Fortumor tissue, % CD8 cells of CD3 cells (FIG. 27I), % CD4 of CD3 cells(FIG. 27J), % NK cells of CD3− cells (FIG. 27K), % FoxP3 of CD4 cells(FIG. 27L) is shown.

FIGS. 28A-28I show results from in vivo T cell activation in spleen,blood, and tumor, using the AK235, AK191, AK192, AK193, AK210, AK189,AK190, or AK211 construct. T cell activation was measured as the meanfluorescence intensity (MFI) of CD25 in CD8+ T cells (FIG. 28A; FIG.28D; FIG. 28G), CD4+ T cells (FIG. 28B; FIG. 28E; FIG. 28H), or Foxp3+cells (FIG. 28C; FIG. 28F; FIG. 28I) in the spleen, blood, and tumor.Statistical analysis was performed using One-way ANOVA as compared tothe non-cleavable AK211 construct.

FIGS. 29A-29D show the results from studies testing the in vivo cleavageof the exemplary masked IL-2 polypeptide constructs AK168 (cleavablepeptide sequence: MPYDLYHP; SEQ ID NO: 96) and AK209 (cleavable peptidesequence: VPLSLY; SEQ ID NO: 135). FIG. 29E shows results from apharmacokinetic study of total plasma IgG concentration (μg/mL) fortotal levels of the AK167, AK168, and AK209 constructs, and for levelsof non-cleaved forms of each construct.

FIGS. 30A-30D shows results from an in vivo study that assessed vascularleakage using the exemplary masked IL-2 polypeptide construct AK111 orAK168, or the non-masked IL-2 polypeptide construct AK081 or AK167, oran anti-RSV control. FIG. 30A shows the percentage (%) of body weightloss, and FIGS. 30B, 30C, and 30D shows the weight in grams of theliver, lung, and spleen, respectively, for each.

FIGS. 31A and 31B shows results from an in vivo study that assessedvascular leakage as indicated by measuring the extent of dye leakageinto liver and lung tissue following administration of the AK081, AK111,AK167, or AK168 construct, or an anti-RSV control. The extent of dyeleakage into liver (FIG. 31A) and lung (FIG. 31B) was measured based onabsorbance at 650 nm.

FIGS. 32A and 32B shows results from an in vivo study that assessedvascular leakage as indicated by measuring the extent of mononuclearcell perivascular invasion into into the liver and lung tissue followingadministration of the AK081, AK111, AK167, or AK168 construct, or ananti-RSV control. The average number of mononuclear cells in the liver(FIG. 32A) and the average number of mononuclear cells in the lung (FIG.32B) depicted for each.

FIGS. 33A and 33B show results from a syngeneic tumor model study thatassessed tumor volume and body weight over the course of treatment withthe AK032, AK081, AK111, AK167, or AK168 construct, or an anti-RSVcontrol. FIG. 33A shows data on tumor volume over the course oftreatment, and FIG. 33B shows data on the percentage (%) change in bodyweight over the course of the treatment.

DETAILED DESCRIPTION

Provided herein are cytokines or functional fragments thereof that, insome embodiments, are engineered to be masked by a masking moiety at oneor more receptor binding site(s) of the cytokine or functional fragmentthereof. In some embodiments, the cytokines are engineered to beactivatable by a protease at a target site, such as in a tumormicroenvironment, by including a proteolytically cleavable linker. Insome embodiments, the proteolytically cleavable linker links thecytokine to the masking moiety, links the cytokine to a half-lifeextension domain, and/or links the masking moiety to a half-lifeextension domain. The masking moiety blocks, occludes, inhibits (e.g.,decreases) or otherwise prevents (e.g., masks) the activity or bindingof the cytokine to its cognate receptor or protein. Upon proteolyticcleavage of the cleavable linker at the target site, the cytokinebecomes activated, which renders it capable of binding to its cognatereceptor or protein with increased affinity.

By using a masking moiety, the systemic side effects of an administeredcytokine can be reduced by interfering with the binding capability ofthe cytokine. For instance, high-dose recombinant IL-2 (aldesleukin) hasbeen approved by the FDA for the treatment of metastatic renal cellcarcinoma and melanoma, but has been associated with severecardiovascular, hepatic, pulmonary, gastrointestinal, neurologic, andhematological side effects. Preclinical studies showed, for instance,that IL-2-induced pulmonary edema is caused by the interaction betweenIL-2 and the IL-2Rα (CD25) subunit of the IL-2 receptor (IL-2R) on lungendothelial cells, and that this IL-2-mediated pulmonary adema could beabrogated by interfering with the ability of the IL-2 to bind IL-2Rα.See Krieg et al. (2010) PNAS, 107(26): 11906-11911. Thus, in someembodiments where the cytokine or functional fragment thereof is an IL-2polypeptide, a masking moiety is employed that blocks, occludes,inhibits (e.g., decreases) or otherwise prevents (e.g., masks) theactivity or binding of an IL-2 cytokine to IL-2Rα. To further reducesystemic effects of a masked IL-2 polypeptide, the masked IL-2polypeptide can further include a masking moiety that blocks, occludes,inhibits (e.g., decreases) or otherwise prevents (e.g., masks) theactivity or binding of the IL-2 cytokine to the IL-2R13 and/or IL-2Rγsubunits of IL-2R. Similar strategies are likewise employed for othercytokines by interfering with their ability to bind certain proteins(e.g., a receptor subunit(s)) that are associated with causingdetrimental systemic side effects. Moreover, by masking the cytokineusing a linker that includes cleavable peptide, the binding capabilitythat is interfered with by using the masking moiety can be restored bycleavage of the cleavable peptide at the tumor microenvironment. Thus,in some embodiments, the masked cytokines provided herein are engineeredto precisely target pharmacological activity to the tumormicroenvironment by exploiting one of the hallmarks of cancer, highlocal concentrations of active protease. This feature of the tumormicroenvironment is used to transform a systemically inert molecule intoa locally active cytokine. Activation of the cytokine at the tumormicroenvironment significantly reduces systemic toxicities that can beassociated with drugs that are administered to a subject in active form.

All publications, including patent documents, scientific articles anddatabases, referred to in this application are incorporated by referencein their entirety for all purposes to the same extent as if eachindividual publication were individually incorporated by reference. If adefinition set forth herein is contrary to or otherwise inconsistentwith a definition set forth in the patents, applications, publishedapplications and other publications that are herein incorporated byreference, the definition set forth herein prevails over the definitionthat is incorporated herein by reference.

The section headings used herein are for organizational purposes onlyand are not to be construed as limiting the subject matter described.

I. MASKED CYTOKINES

Provided herein, in some embodiments, is a masked cytokine comprising(a) a masking moiety; and (b) a cytokine or functional fragment thereof,wherein the masking moiety is linked to the cytokine or functionalfragment thereof via a first linker. In some embodiments, the maskedcytokine further comprises a half-life extension domain that is linkedto either the masking moiety or the cytokine or functional fragmentthereof. In some embodiments, the half-life extension domain is linkedto either the masking moiety or the IL-2 polypeptide or functionalfragment thereof via a second linker.

In some embodiments, the masked cytokine comprises in an N to C-terminaldirection: (a) the masking moiety; (b) the first linker; (c) thecytokine or functional fragment thereof; and (d) the half-life extensiondomain. In some embodiments, the masked cytokine comprises in a C toN-terminal direction: (a) the masking moiety; (b) the first linker; (c)the cytokine or functional fragment thereof; and (d) the half-lifeextension domain. In some embodiments, the masked cytokine comprises inan N to C-terminal direction: (a) the masking moiety; (b) the firstlinker; (c) the cytokine or functional fragment thereof; (d) the secondlinker and (e) the half-life extension domain. In some embodiments, themasked cytokine comprises in a C to N-terminal direction: (a) themasking moiety; (b) the first linker; (c) the cytokine or functionalfragment thereof; (d) the second linker and (e) the half-life extensiondomain. In some embodiments, the masked cytokine comprises in an N toC-terminal direction: (a) the cytokine or functional fragment thereof;(b) the first linker; (c) the masking moiety; and (d) the half-lifeextension domain. In some embodiments, the masked cytokine comprises ina C to N-terminal direction: (a) the cytokine or functional fragmentthereof; (b) the first linker; (c) the masking moiety; and (d) thehalf-life extension domain. In some embodiments, the masked cytokinecomprises in an N to C-terminal direction: (a) the cytokine orfunctional fragment thereof; (b) the first linker; (c) the maskingmoiety; (d) the second linker; and (e) the half-life extension domain.In some embodiments, the masked cytokine comprises in a C to N-terminaldirection: (a) the cytokine or functional fragment thereof; (b) thefirst linker; (c) the masking moiety; (d) the second linker; and (e) thehalf-life extension domain. In some embodiments, the masked cytokinecomprises in an N to C-terminal direction: (a) the half-life extensiondomain; (b) the first linker; (c) the masking moiety; (d) the secondlinker; and (e) the cytokine or functional fragment thereof. In someembodiments, the masked cytokine comprises in an N to C-terminaldirection: (a) the half-life extension domain; (b) the cytokine orfunctional fragment thereof; (c) the first linker; and (d) the maskingmoiety. In some embodiments, the masked cytokine comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:585-597, 602, 610-614, 627-636, 642, and 643. In some embodiments, themasked cytokine comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 585-597, 602, 610-614, 627-636, 642, and 643.In some embodiments, the masked cytokine is any of the exemplaryconstructs described in Table 4 or Table 5, or is variant created bymodifying any of the exemplary constructs described in Table 4 or Table5, such as by incorporating one or more additional components to thestructure of the construct in accordance with the teachings herein.

Also provided herein, in some embodiments, is a masked cytokinecomprising (a) a first masking moiety; (b) a cytokine or functionalfragment thereof, wherein the first masking moiety is linked to thecytokine or functional fragment thereof via a first linker; and (c) asecond masking moiety, wherein the second masking moiety is linked tothe cytokine or functional fragment thereof via a second linker. In someembodiments, the masked cytokine further comprises a half-life extensiondomain that is linked to either the first masking moiety or the secondmasking moiety. In some embodiments, the half-life extension domain islinked to either the first masking moiety or the second masking moietyvia a third linker.

Also provided herein, in some embodiments, is a masked cytokinecomprising (a) a first masking moiety, wherein the first masking moietyis linked to a first half-life extension domain; (b) a cytokine orfunctional fragment thereof, wherein the cytokine or functional fragmentthereof is linked to a second half-life extension domain; and (c) asecond masking moiety, wherein the second masking moiety is linked tothe first masking moiety. In some embodiments, the first masking moietyis linked to the first half-life extension domain via a first linker. Insome embodiments, the second masking moiety is linked to the firstmasking moiety via a second linker. In some embodiments, the cytokine orfunctional fragment thereof is linked to the second half-life extensiondomain via a third linker. In some embodiments, the first linkercomprises a cleavable peptide. In some embodiments, the second linkercomprises a cleavable peptide. In some embodiments, the third linkercomprises a cleavable peptide.

In some embodiments, the masked cytokine comprises in an N to C-terminaldirection: (a) the first masking moiety; (b) the first linker; (c) thecytokine or functional fragment thereof; (d) a second linker; (e) asecond masking moiety; and (f) the half-life extension domain. In someembodiments, the masked cytokine comprises in a C to N-terminaldirection: (a) the first masking moiety; (b) the first linker; (c) thecytokine or functional fragment thereof; (d) a second linker; (e) asecond masking moiety; and (f) the half-life extension domain. In someembodiments, the masked cytokine comprises in an N to C-terminaldirection: (a) the first masking moiety; (b) the first linker; (c) thecytokine or functional fragment thereof; (d) a second linker; (e) asecond masking moiety; (f) the third linker; and (g) the half-lifeextension domain. In some embodiments, the masked cytokine comprises ina C to N-terminal direction: (a) the first masking moiety; (b) the firstlinker; (c) the cytokine or functional fragment thereof; (d) a secondlinker; (e) a second masking moiety; (f) the third linker; and (g) thehalf-life extension domain. In some embodiments, the masked cytokinecomprises in an N to C-terminal direction: (a) the half-life extensiondomain; (b) a first linker; (c) the first masking moiety; (d) a secondlinker; (e) the cytokine or functional fragment thereof; (f) a thirdlinker; and (g) the second masking moiety. In some embodiments, themasked cytokine comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 567 and 598-601. In some embodiments, themasked cytokine comprises an amino acid sequence having about or atleast about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, or 99% sequence identity to an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 567 and 598-601. In someembodiments, the masked cytokine is any of the exemplary constructsdescribed in Table 6 or Table 7, or is variant created by modifying anyof the exemplary constructs described in Table 6 or Table 7, such as byincorporating one or more additional components to the structure of theconstruct in accordance with the teachings herein.

Also provided herein, in some embodiments, is a masked cytokinecomprising (a) a first half-life extension domain and a second half-lifeextension domain; (b) a masking moiety; and (c) a cytokine or functionalfragment thereof, wherein the masking moiety is linked to the firsthalf-life extension domain, the cytokine or functional fragment thereofis linked to the second half-life extension domain, and the firsthalf-life extension domain and the second half-life extension domaincontain modifications promoting the association of the first and thesecond half-life extension domain. In some embodiments, the maskingmoiety is linked to the first half-life extension domain via a firstlinker, and/or the cytokine or functional fragment thereof is linked tothe second half-life extension domain via a second linker. In someembodiments, the first half-life extension domain is linked to thesecond half-life extension domain, optionally by a third linker. In someembodiments, the masked cytokine comprises (a) a first half-lifeextension domain comprising the amino acid sequence of SEQ ID NO: 155and a second half-life extension domain comprising the amino acidsequence of SEQ ID NO: 156; (b) a masking moiety comprising the aminoacid sequence of SEQ ID NO: 261; and (c) a cytokine or functionalfragment thereof comprising the amino acid sequence of SEQ ID NO: 3,wherein the masking moiety is linked to the first half-life extensiondomain via a first linker comprising the amino acid sequence of SEQ IDNO: 28, the cytokine or functional fragment thereof is linked to thesecond half-life extension domain via a second linker comprising theamino acid sequence of SEQ ID NO: 811, the first half-life extensiondomain and the second half-life extension domain contain modificationspromoting the association of the first and the second half-lifeextension domain, and the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 266 and 267. In some embodiments, the maskedcytokine comprises (a) a first half-life extension domain comprising theamino acid sequence of SEQ ID NO: 155 and a second half-life extensiondomain comprising the amino acid sequence of SEQ ID NO: 156; (b) amasking moiety comprising the amino acid sequence of SEQ ID NO: 261; and(c) a cytokine or functional fragment thereof comprising the amino acidsequence of SEQ ID NO: 260, wherein the masking moiety is linked to thefirst half-life extension domain via a first linker comprising the aminoacid sequence of SEQ ID NO: 28, the cytokine or functional fragmentthereof is linked to the second half-life extension domain via a secondlinker comprising the amino acid sequence of SEQ ID NO: 262, the firsthalf-life extension domain and the second half-life extension domaincontain modifications promoting the association of the first and thesecond half-life extension domain, and the masked cytokine comprises theamino acid sequences of SEQ ID NOs: 266 and 267. In some embodiments,the masked cytokine comprises the amino acid sequence of SEQ ID NO: 266.In some embodiments, the masked cytokine comprises the amino acidsequence of SEQ ID NO: 267. In some embodiments, the masked cytokinecomprises the amino acid sequences of SEQ ID NOs: 266 and 267. In someembodiments, the masked cytokine comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 266. In some embodiments, the masked cytokinecomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267. In someembodiments, the masked cytokine comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 266, and comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises (a) a first half-lifeextension domain comprising the amino acid sequence of SEQ ID NO: 155and a second half-life extension domain comprising the amino acidsequence of SEQ ID NO: 156; (b) a masking moiety comprising the aminoacid sequence of SEQ ID NO: 261; and (c) a cytokine or functionalfragment thereof comprising the amino acid sequence of SEQ ID NO: 3,wherein the masking moiety is linked to the first half-life extensiondomain via a first linker comprising the amino acid sequence of SEQ IDNO: 28, the cytokine or functional fragment thereof is linked to thesecond half-life extension domain via a second linker comprising theamino acid sequence of SEQ ID NO: 807, the first half-life extensiondomain and the second half-life extension domain contain modificationspromoting the association of the first and the second half-lifeextension domain, and the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 679 and 267. In some embodiments, the maskedcytokine comprises (a) a first half-life extension domain comprising theamino acid sequence of SEQ ID NO: 156 and a second half-life extensiondomain comprising the amino acid sequence of SEQ ID NO: 155; (b) amasking moiety comprising the amino acid sequence of SEQ ID NO: 261; and(c) a cytokine or functional fragment thereof comprising the amino acidsequence of SEQ ID NO: 3, wherein the masking moiety is linked to thefirst half-life extension domain via a first linker comprising the aminoacid sequence of SEQ ID NO: 28, the cytokine or functional fragmentthereof is linked to the second half-life extension domain via a secondlinker comprising the amino acid sequence of SEQ ID NO: 807, the firsthalf-life extension domain and the second half-life extension domaincontain modifications promoting the association of the first and thesecond half-life extension domain, and the masked cytokine comprises theamino acid sequences of SEQ ID NOs: 679 and 267.

In some embodiments, the masked cytokine comprises (a) a first half-lifeextension domain comprising the amino acid sequence of SEQ ID NO: 155and a second half-life extension domain comprising the amino acidsequence of SEQ ID NO: 156; (b) a masking moiety comprising the aminoacid sequence of SEQ ID NO: 261; and (c) a cytokine or functionalfragment thereof comprising the amino acid sequence of SEQ ID NO: 3,wherein the masking moiety is linked to the first half-life extensiondomain via a first linker, the cytokine or functional fragment thereofis linked to the second half-life extension domain via a second linker,the first half-life extension domain and the second half-life extensiondomain contain modifications promoting the association of the first andthe second half-life extension domain, wherein the first linker and/orthe second linker comprises a cleavable peptide. In some embodiments,the masked cytokine comprises (a) a first half-life extension domaincomprising the amino acid sequence of SEQ ID NO: 156 and a secondhalf-life extension domain comprising the amino acid sequence of SEQ IDNO: 155; (b) a masking moiety comprising the amino acid sequence of SEQID NO: 261; and (c) a cytokine or functional fragment thereof comprisingthe amino acid sequence of SEQ ID NO: 3, wherein the masking moiety islinked to the first half-life extension domain via a first linker, thecytokine or functional fragment thereof is linked to the secondhalf-life extension domain via a second linker, the first half-lifeextension domain and the second half-life extension domain containmodifications promoting the association of the first and the secondhalf-life extension domain, wherein the first linker and/or the secondlinker comprises a cleavable peptide.

In some embodiments, the masked cytokine comprises (a) a first half-lifeextension domain comprising the amino acid sequence of SEQ ID NO: 155and a second half-life extension domain comprising the amino acidsequence of SEQ ID NO: 156; (b) a masking moiety comprising the aminoacid sequence of SEQ ID NO: 261; and (c) a cytokine or functionalfragment thereof comprising the amino acid sequence of SEQ ID NO: 1,wherein the masking moiety is linked to the first half-life extensiondomain via a first linker comprising the amino acid sequence of SEQ IDNO: 28, the cytokine or functional fragment thereof is linked to thesecond half-life extension domain via a second linker comprising theamino acid sequence of SEQ ID NO: 812, the first half-life extensiondomain and the second half-life extension domain contain modificationspromoting the association of the first and the second half-lifeextension domain, and the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 689 and 267. In some embodiments, the maskedcytokine comprises (a) a first half-life extension domain comprising theamino acid sequence of SEQ ID NO: 156 and a second half-life extensiondomain comprising the amino acid sequence of SEQ ID NO: 155; (b) amasking moiety comprising the amino acid sequence of SEQ ID NO: 261; and(c) a cytokine or functional fragment thereof comprising the amino acidsequence of SEQ ID NO: 1, wherein the masking moiety is linked to thefirst half-life extension domain via a first linker comprising the aminoacid sequence of SEQ ID NO: 28, the cytokine or functional fragmentthereof is linked to the second half-life extension domain via a secondlinker comprising the amino acid sequence of SEQ ID NO: 812, the firsthalf-life extension domain and the second half-life extension domaincontain modifications promoting the association of the first and thesecond half-life extension domain, and the masked cytokine comprises theamino acid sequences of SEQ ID NOs: 689 and 267.

In some embodiments, the masked cytokine comprises (a) a first half-lifeextension domain comprising the amino acid sequence of SEQ ID NO: 155and a second half-life extension domain comprising the amino acidsequence of SEQ ID NO: 156; (b) a masking moiety comprising the aminoacid sequence of SEQ ID NO: 261; and (c) a cytokine or functionalfragment thereof comprising the amino acid sequence of SEQ ID NO: 1,wherein the masking moiety is linked to the first half-life extensiondomain via a first linker, the cytokine or functional fragment thereofis linked to the second half-life extension domain via a second linker,the first half-life extension domain and the second half-life extensiondomain contain modifications promoting the association of the first andthe second half-life extension domain, wherein the first linker and/orthe second linker comprises a cleavable peptide. In some embodiments,the masked cytokine comprises (a) a first half-life extension domaincomprising the amino acid sequence of SEQ ID NO: 156 and a secondhalf-life extension domain comprising the amino acid sequence of SEQ IDNO: 155; (b) a masking moiety comprising the amino acid sequence of SEQID NO: 261; and (c) a cytokine or functional fragment thereof comprisingthe amino acid sequence of SEQ ID NO: 1, wherein the masking moiety islinked to the first half-life extension domain via a first linker, thecytokine or functional fragment thereof is linked to the secondhalf-life extension domain via a second linker, the first half-lifeextension domain and the second half-life extension domain containmodifications promoting the association of the first and the secondhalf-life extension domain, wherein the first linker and/or the secondlinker comprises a cleavable peptide.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 562 and 563. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 562, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 563.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 608 and 603. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 608, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 603.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 604 and 603. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 604, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 603.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 605 and 603. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 605, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 603.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 606 and 603. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 606, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 603.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 615 and 617. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 615, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 617.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 618 and 620. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 618, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 620.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 621 and 623. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 621, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 623.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 624 and 626. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 624, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 626.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 608 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 608, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 663 and 664. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 663, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 664.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 665 and 666. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 665, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 666.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 667 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 667, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 669 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 669, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 670 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 670, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 672 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 672, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 673 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 673, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 674 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 674, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 675 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 675, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 676 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 676, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 677 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 677, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 678 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 678, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 679 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 679, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 680 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 680, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 681 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 681, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 682 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 682, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 683 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 683, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 684 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 684, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 685 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 685, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 686 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 686, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 687 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 687, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 688 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 688, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 689 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 689, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 690 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 690, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 266 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 266, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 692 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 692, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 693 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 693, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 694 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 694, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 695 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 695, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 696 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 696, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 697 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 697, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 698 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 698, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 699 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 699, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 700 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 700, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 701 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 701, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 702 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 702, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 703 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 703, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 704 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 704, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 705 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 705, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 706 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 706, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 707 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 707, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 708 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 708, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 709 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 709, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 710 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 710, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 711 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 711, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 712 and 667. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 712, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 667.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 713 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 713, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 714 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 714, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 716 and 699. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 716, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 699.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 717 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 717, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 718 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 718, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 719 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 719, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 720 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 720, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 722 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 722, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 723 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 723, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 726 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 720, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 728 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 728, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 729 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 729, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 730 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 730, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 731 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 731, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 732 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 732, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 733 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 733, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 734 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 734, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 735 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 735, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 736 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 736, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 737 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 737, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 738 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 738, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 739 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 739, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 740 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 740, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 741 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 741, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 742 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 742, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 743 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 743, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 744 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 744, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 745 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 745, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 746 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 746, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 674 and 828. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 674, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 828.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 674 and 829. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 674, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 829.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 726 and 830. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 726, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 830.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 726 and 829. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 726, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 829.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 747 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 747, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 715 and 267. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 715, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 267.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 715 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 715, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 748 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 748, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 749 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 749, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 750 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 750, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 751 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 751, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 752 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 752, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 753 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 753, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 754 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 754, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 758 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 758, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 759 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 759, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 760 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 760, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine comprises the amino acidsequences of SEQ ID NOs: 761 and 671. In some embodiments, the maskedcytokine comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 761, andcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 671.

In some embodiments, the masked cytokine is an exemplary masked cytokineconstruct as described in any of Tables 8-11, or is a variant created bymodifying any of the exemplary constructs described in Tabls 8-11, suchas by incorporating one or more additional components to the structureof the construct in accordance with the teachings herein.

Also provided herein, in some embodiments, is a masked cytokinecomprising (a) a first half-life extension domain and a second half-lifeextension domain; (b) a first masking moiety and a second maskingmoiety; and (c) a cytokine or functional fragment thereof, wherein thefirst masking moiety is linked to the first half-life extension domain,the second masking moiety is linked to the cytokine or functionalfragment thereof, either the second masking moiety or the cytokine orfunctional fragment thereof is linked to the second half-life extensiondomain, and the first half-life extension domain and the secondhalf-life extension domain contain modifications promoting theassociation of the first and the second half-life extension domain. Insome embodiments, the first masking moiety is linked to the firsthalf-life extension domain via a first linker, and/or either the secondmasking moiety or the cytokine or functional fragment thereof is linkedto the second half-life extension domain via a second linker. In someembodiments, the second masking moiety is linked to the cytokine orfunctional fragment thereof via a third linker. In some embodiments, thefirst half-life extension domain is linked to the second half-lifeextension domain, optionally by a fourth linker. In some embodiments,the masked cytokine comprises the amino acid sequences of SEQ ID NOs:755 and 616. In some embodiments, the masked cytokine comprises theamino acid sequences of SEQ ID NOs: 756 and 616. In some embodiments,the masked cytokine comprises the amino acid sequences of SEQ ID NOs:757 and 616. In some embodiments, the masked cytokine comprises an aminoacid sequence having about or at least about 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity tothe amino acid sequence of SEQ ID NO: 755, and an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 616. In some embodiments, the masked cytokinecomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 756, and anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 616. In someembodiments, the masked cytokine comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 757, and an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to the amino acid sequence ofSEQ ID NO: 616.

In some embodiments, the masked cytokine comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 265-267,556-720, 722, 723, 726, 728-761, and 828-830. In some embodiments, themasked cytokine comprises two different amino acid sequences selectedfrom the group consisting of SEQ ID NOs: 265-267, 556-720, 722, 723,726, 728-761, and 828-830. In some embodiments, the masked cytokinecomprises the amino acid sequences associated with any of the exemplaryconstructs as described in Tables 4-11.

Each component of the masked cytokines provided herein is discussed ingreater detail below.

A. Cytokines

Provided herein is a cytokine or functional fragment thereof. Thecytokine or functional fragment thereof can be any cytokine, anyfunctional fragment of any cytokine, or any natural or non-naturalvariant of any cytokine. A cytokine is a small polypeptide that plays arole in cellular signaling, particularly in cells of the immune system.Examples of cytokines may include chemokines, interferons, interleukins,lymphokines, and tumor necrosis factors.

Cytokines can be classified in a variety of ways, such as based on theirthree-dimensional structure. Examples include the β-trefoil fold class,the short-chain four-helix bundle class, and the long-chain four-helixbundle class.

The β-trefoil fold class includes cytokines that are characterized bythree βββ-loop-β units (12 β strands total) that form a barrel structurewith a hairpin cap for the barrel. Examples of cytokines in theβ-trefoil fold class include IL-1α, IL-1β, IL-1 receptor antagonist(IL-1RA), IL-18, IL-33, IL-36 α, IL-36 β, IL-36γ, IL-36 receptorantagonist (IL-36RA), IL-37, and IL-38.

Short-chain and long-chain four-helix bundle classes are characterizedby a monomeric helical bundle having four amphipathic helices orientedin a unique up-up-down-down topology. The short-chain four-helix bundleclass is characterized by shorter helices, such as those 10-20 aminoacid residues in length, while the long-chain four-helix bundle class ischaracterized by longer helices, such as those 20-30 amino acid residuesin length. Examples of cytokines in the short-chain four-helix bundleclass include IL-2, IL-3, IL-4, IL-5, IL-7, IL-9, IL-13, IL-15, IL-21,granulocyte-macrophage colony-stimulating factor (GM-CSF), andmacrophage colony-stimulating factor (M-CSF). Examples of cytokine inthe long-chain four-helix bundle class include IL-6, IL-11, IL-12,growth hormone (GH), erythropoietin (EPO), prolactin (PRL), leukemiainhibitory factor (LIF), oncostatin (OSM), and thrombopoietin (TPO).

In contrast to the short- and long-chain four-helix bundle classes,which are monomeric, some cytokines are homodimeric. Examples of dimericcytokines include IL-10 and IFN-γ (gamma).

Some cytokines are classified as being heterodimeric. Examples ofheterodimeric cytokines include IL-12 and IL-23.

Some cytokines, such as IL-15, also function by binding to, and beingpresented by, a membrane-bound cytokine receptor.

In some embodiments, the cytokine or functional fragment thereof isIL-2, or is a functional fragment or variant of IL-2. In someembodiments, the cytokine or functional fragment thereof is IL-15, or isa functional fragment or variant of IL-15. In some embodiments, thecytokine or functional fragment thereof is selected from the groupconsisting of IL-2, IL-10, IL-12, IL-15, IL-18, interferon (IFN)-α(alpha), IFN-β (beta), and IFN-γ (gamma). In some embodiments, thecytokine or functional fragment thereof is a functional fragment orvariant of IL-2, IL-10, IL-12, IL-15, IL-18, IFN-α (alpha), IFN-β(beta), or IFN-γ (gamma).

In some embodiments, the cytokine or functional fragment thereof isselected from the group consisting of IL-1α, IL-1β, IL-1 receptorantagonist (IL-1RA), IL-18, IL-33, IL-36 α, IL-36 β, IL-36γ, IL-36receptor antagonist (IL-36RA), IL-37, and IL-38.

In some embodiments, the cytokine or functional fragment thereof isselected from the group consisting of IL-2, IL-3, IL-4, IL-5, IL-7,IL-9, IL-13, IL-15, IL-21, granulocyte-macrophage colony-stimulatingfactor (GM-CSF), macrophage colony-stimulating factor (M-CSF), IL-6,IL-11, IL-12, growth hormone (GH), erythropoietin (EPO), prolactin(PRL), leukemia inhibitory factor (LIF), oncostatin (OSM), andthrombopoietin (TPO).

In some embodiments, the cytokine or functional fragment thereof isselected from the group consisting of CXCL1, CXCL2, CXCL3, CXCL4, CXCL5,CXCL6, CXCL7, CXCL8, CXCL9, CXCL10, CXCL11, CXCL12, CXCL13, CXCL14,CXCL15, CXCL16, CCL1e, CCL2, CCL3, CCL3L1, CCL4, CCL5, CCL6, CCL7, CCL8,CCL9/10, CCL11, CCL12, CCL13, CCL14, CCL15, CCL16, CCL17, CCL18, CCL19,CCL20, CCL21, CCL22, CCL23, CCL24, CCL25, CCL26, CCL27, CCL28, CX3CL1,XCL1, and XCL2. In some embodiments, the cytokine or functional fragmentthereof is a functional fragment or variant of CXCL1, CXCL2, CXCL3,CXCL4, CXCL5, CXCL6, CXCL7, CXCL8, CXCL9, CXCL10, CXCL11, CXCL12,CXCL13, CXCL14, CXCL15, CXCL16, CCL1e, CCL2, CCL3, CCL3L1, CCL4, CCL5,CCL6, CCL7, CCL8, CCL9/10, CCL11, CCL12, CCL13, CCL14, CCL15, CCL16,CCL17, CCL18, CCL19, CCL20, CCL21, CCL22, CCL23, CCL24, CCL25, CCL26,CCL27, CCL28, CX3CL1, XCL1, or XCL2.

In some embodiments, the cytokine or functional fragment thereof isselected from the group consisting of IFN-α (alpha), IFN-β (beta), IFN-γ(gamma), IFN-ε (epsilon), IFN-κ (kappa), IFN-{dot over (ω)} (omega),IFN-τ (tau), IFN-ζ (zeta), IFN-δ (delta), and IFN-λ, (lambda). In someembodiments, the cytokine or functional fragment thereof is a functionalfragment or variant of IFN-α (alpha), IFN-β (beta), IFN-γ (gamma), IFN-ε(epsilon), IFN-κ (kappa), IFN-{dot over (ω)} (omega), IFN-τ (tau), IFN-ζ(zeta), IFN-δ (delta), or IFN-λ (lambda).

In some embodiments, the cytokine or functional fragment thereof isselected from the group consisting of IL-1, IL-2, IL-3, IL-4, IL-5,IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, IL-14, IL-15, IL-16,IL-17, IL-18, IL-19, IL-20, IL-21, IL-22, IL-23, IL-24, IL-25, IL-26,IL-27, IL-28A, IL-28B, IL-29, IL-30, IL-31, IL-32, IL-33, IL-34, IL-35,IL-36, and IL-37. In some embodiments, the cytokine or functionalfragment thereof is a functional fragment or variant of IL-1, IL-2,IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13,IL-14, IL-15, IL-16, IL-17A, IL-17C, IL-17D, IL-17F, IL-17A/F, IL-18,IL-19, IL-20, IL-21, IL-22, IL-23, IL-24, IL-25, IL-26, IL-27, IL-28A,IL-28B, IL-29, IL-30, IL-31, IL-32, IL-33, IL-34, IL-35, IL-36, orIL-37.

In some embodiments, the cytokine or functional fragment thereof isselected from the group consisting of granulocyte-macrophagecolony-stimulating factor (GM-CSF), macrophage colony-stimulating factor(M-CSF), tumor necrosis factor alpha (TNF-α), transforming growth factorbeta (TGF-β), IFN-γ (gamma), IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8,and IL-12. In some embodiments, the cytokine or functional fragmentthereof is a functional fragment or variant of granulocyte-macrophagecolony-stimulating factor (GM-CSF), macrophage colony-stimulating factor(M-CSF), tumor necrosis factor alpha (TNF-α), transforming growth factorbeta (TGF-β), IFN-γ (gamma), IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8,or IL-12.

In some embodiments, the cytokine or functional fragment thereof isselected from the group consisting of TNF-α (alpha), TNF-β (beta), TNF-γ(gamma), CD252, CD154, CD178, CD70, CD153, 4-1BB-L, TRAIL, RANKL, APO3L,CD256, CD257, CD258, TL1, AITRL, and EDA1. In some embodiments, thecytokine or functional fragment thereof is a functional fragment orvariant of TNF-α (alpha), TNF-β (beta), TNF-γ (gamma), CD252, CD154,CD178, CD70, CD153, 4-1BB-L, TRAIL, RANKL, APO3L, CD256, CD257, CD258,TL1, AITRL, and EDA1.

The cytokine or functional fragment thereof comprises an amino-terminusand a carboxy-terminus. In some embodiments, a half-life extensiondomain is linked to the amino-terminus or the carboxy-terminus of thecytokine or functional fragment thereof. In some embodiments, a maskingmoiety is linked to the amino-terminus or the carboxy-terminus of thecytokine or functional fragment thereof. In some embodiments, a linkeris linked to the amino-terminus or the carboxy-terminus of the cytokineor functional fragment thereof. In some embodiments, a cleavable peptideof a linker is linked to the amino-terminus or the carboxy-terminus ofthe cytokine or functional fragment thereof. In some embodiments, anN-terminal spacer domain or a C-terminal spacer domain of a linker islinked to the amino-terminus or the carboxy-terminus of the cytokine orfunctional fragment thereof.

Exemplary embodiments of the cytokine or functional fragment thereof inthe form of IL-2 polypeptides or functional fragments thereof, and IL-15polypeptides or functional fragments thereof, are provided below indetail.

1. IL-2 Polypeptides

In some embodiments, the cytokine or functional fragment thereof is anIL-2 polypeptide or functional fragment thereof. In eukaryotic cells,IL-2 is synthesized as a precursor polypeptide of 153 amino acids, whichis then processed into mature IL-2 by the removal of amino acid residues1-20. This results in a mature form of IL-2 consisting of 133 aminoacids (amino acid residues 21-153) that is secreted in a mature, activeform.

In some embodiments, the IL-2 polypeptide or functional fragment thereofis any naturally occurring interleukin-2 (IL-2) protein or modifiedvariant thereof capable of binding to, or otherwise exhibiting affinityfor, an interleukin-2 receptor (IL-2R) or component thereof (e.g., theIL-2Rα chain). In some embodiments, the IL-2 polypeptide or functionalfragment thereof is a mature form of IL-2 that consists of amino acidresidues 21-153 of SEQ ID NO: 159. In some embodiments, the IL-2polypeptide or functional fragment thereof comprises the amino acidsequence of SEQ ID NO: 160. In some embodiments, the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 1-8 and 260. In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises the amino acid sequence of SEQ ID NO: 260. In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 1-8, 160, 230, 243-251, 260, 775-792, and 813-822. In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822.In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises the amino acid sequence of SEQ ID NO: 230. In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 230. In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises the amino acid sequence of SEQ ID NO: 3. In some embodiments,the IL-2 polypeptide or functional fragment thereof comprises an aminoacid sequence having about or at least about 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity tothe amino acid sequence of SEQ ID NO: 3.

In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by at least one amino acidmodification to an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 1-8, 160, 230, 243-251, 260, 775-792, and813-822. Each of the at least one amino acid modifications can be anyamino acid modification, such as a substitution, insertion, or deletion.In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by at least 1, at least 2, atleast 3, at least 4, at least 5, at least 6, at least 7, at least 8, atleast 9, or at least 10 amino acid substitutions in the amino acidsequence of any one of SEQ ID NOs: 1-8, 160, 230, 243-251, 260, 775-792,and 813-822. In some embodiments, the IL-2 peptide or functionalfragment thereof comprises an amino acid sequence that comprises aserine (S), glycine (G), or alanine (A) residue at amino acid residue125. In some embodiments the IL-2 peptide or functional fragment thereofcomprises an amino acid sequence that comprises an alanine (A) residueat amino acid residue 3. For example, in some embodiments, the IL-2peptide or functional fragment thereof comprises an amino acid sequenceproduced by introducing a T3A amino acid substitution to an amino acidsequence selected from the group consisting of SEQ ID NOs: 1-8 and 160.In some embodiments, the IL-2 peptide or functional fragment thereofcomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 243-251 and 260. In some embodiments, the IL-2 peptide orfunctional fragment thereof comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 775-792, and 813-822.

In some embodiments, the IL-2 peptide or functional fragment thereofcomprises an amino acid sequence having one or more amino acidsubstitutions compared to the amino acid sequence of wildtype IL-2 thatreduces the affinity of the IL-2 peptide or functional fragment thereoffor IL-2Rα (CD25). In some embodiments, the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byone or more amino acid substitutions in the amino acid sequence of anyone of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, suchthat one or more of amino acid residues 38, 42, 45, and 62 is an alanine(A). In some embodiments, the IL-2 polypeptide or functional fragmentthereof comprises an amino acid sequence produced by one or more aminoacid substitutions in the amino acid sequence of any one of SEQ ID NOs:1-8, 160, 243-251, 260, 775-792, and 813-822, such that amino acidresidues 38, 42, 45, and 62 are an alanine (A). In some embodiments, theIL-2 polypeptide or functional fragment thereof comprises an amino acidsequence produced by one or more amino acid substitutions in the aminoacid sequence of any one of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792,and 813-822, such that amino acid residues 38, 42, 45, and 62 are analanine (A) and amino acid residue 125 is a serine (S), glycine (G), oralanine (A). In some embodiments, the IL-2 polypeptide or functionalfragment thereof comprises an amino acid sequence produced by one ormore amino acid substitutions in the amino acid sequence of any one ofSEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, such thatamino acid residues 38 and 42 are an alanine (A) and amino acid residue125 is a serine (S), glycine (G), or alanine (A). In some embodiments,the IL-2 polypeptide or functional fragment thereof comprises an aminoacid sequence produced by substituting amino acid residues R38, F42,Y45, and E62 for alanine in the amino acid sequence of SEQ ID NO: 160 or251. In some embodiments, the IL-2 polypeptide or functional fragmentthereof comprises an amino acid sequence produced by substituting aminoacid residues R38, F42, Y45, and E62 for alanine (A) and by substitutingamino acid residue C125 for serine (S), glycine (G), or alanine (A) inthe amino acid sequence of SEQ ID NO: 160 or 251. In some embodiments,the IL-2 polypeptide or functional fragment thereof comprises an aminoacid sequence produced by one or more amino acid substitutions in theamino acid sequence of any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822, such that amino acid residue 42 is lysine (K). Insome embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by one or more amino acidsubstitutions in the amino acid sequence of any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822, such that amino acid residue 42is lysine (K) and amino acid residue 125 is a serine (S), glycine (G),or alanine (A). In some embodiments, the IL-2 polypeptide or functionalfragment thereof comprises an amino acid sequence produced by one ormore amino acid substitutions in the amino acid sequence of any one ofSEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, such thatamino acid residues 42 and 45 are alanine (A) and amino acid residue 72is glycine (G). In some embodiments, the IL-2 polypeptide or functionalfragment thereof comprises an amino acid sequence produced by one ormore amino acid substitutions in the amino acid sequence of any one ofSEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, such thatamino acid residues 42 and 45 are alanine (A), amino acid residue 72 isglycine (G), and amino acid residue 125 is a serine (S), glycine (G), oralanine (A). In some embodiments, the IL-2 polypeptide or functionalfragment thereof comprises an amino acid sequence produced by one ormore amino acid substitutions in the amino acid sequence of any one ofSEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, such thatamino acid residue 62 is an arginine (R) or serine (S). In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by one or more amino acidsubstitutions in the amino acid sequence of any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822, such that amino acid residue 42is glutamic acid (E). In some embodiments, the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byone or more amino acid substitutions in the amino acid sequence of anyone of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, suchthat amino acid residue 43 is alanine (A). In some embodiments, the IL-2polypeptide or functional fragment thereof comprises an amino acidsequence produced by one or more amino acid substitutions in the aminoacid sequence of any one of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792,and 813-822, such that amino acid residue 45 is asparagine (N), arginine(R), or alanine (A). In some embodiments, the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byone or more amino acid substitutions in the amino acid sequence of anyone of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, suchthat amino acid residue 45 is alanine (A) and amino acid residue 62 isserine (S). In some embodiments, the IL-2 polypeptide or functionalfragment thereof comprises an amino acid sequence produced by one ormore amino acid substitutions in the amino acid sequence of any one ofSEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, such thatamino acid residue 42 is serine (S), amino acid residue 62 is serine(S). In some embodiments, the IL-2 polypeptide or functional fragmentthereof comprises an amino acid sequence produced by one or more aminoacid substitutions in the amino acid sequence of any one of SEQ ID NOs:1-8, 160, 243-251, 260, 775-792, and 813-822, such that amino acidresidue 38 is glycine (G), amino acid residue 45 is alanine (A), andamino acid residue 62 is serine (S).

In some embodiments, the IL-2 peptide or functional fragment thereofcomprises an amino acid sequence produced by introducing one or more ofthe following amino acid substitutions into any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822: R38A, F42A, F42E, F42K, K43A,Y45A, Y45N, Y45R, E62A, E62R, E62S, L72G, C125S, C125G, and C125A.

In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence having one or more amino acidsubstitutions compared to the amino acid sequence of wildtype IL-2 thatenhances the affinity of the IL-2 polypeptide or functional fragmentthereof for IL-2Rβ (CD122). In some embodiments, the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byone or more amino acid substitutions in the amino acid sequence of anyone of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, suchthat amino acid residue 80 is phenylalanine (F), amino acid residue 81is aspartic acid (D), amino acid residue 85 is valine (V), amino acidresidue 86 is valine (V), or amino acid residue 92 is phenylalanine (F),or combinations thereof. In some embodiments, the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byone or more amino acid substitutions in the amino acid sequence of anyone of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, suchthat amino acid residue 80 is phenylalanine (F), amino acid residue 81is aspartic acid (D), amino acid residue 85 is valine (V), amino acidresidue 86 is valine (V), or amino acid residue 92 is phenylalanine (F),or combinations thereof, and amino acid residue 125 is serine (S),glycine (G), or alanine (A). In some embodiments, the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby one or more amino acid substitutions in the amino acid sequence ofany one of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822,such that amino acid residue 80 is phenylalanine (F), amino acid residue81 is aspartic acid (D), amino acid residue 85 is valine (V), amino acidresidue 86 is valine (V), and amino acid residue 92 is phenylalanine(F). In some embodiments, the IL-2 polypeptide or functional fragmentthereof comprises an amino acid sequence produced by one or more aminoacid substitutions in the amino acid sequence of any one of SEQ ID NOs:1-8, 160, 243-251, 260, 775-792, and 813-822, such that amino acidresidue 80 is phenylalanine (F), amino acid residue 81 is aspartic acid(D), amino acid residue 85 is valine (V), amino acid residue 86 isvaline (V), amino acid residue 92 is phenylalanine (F), and amino acidresidue 125 is serine (S), glycine (G), or alanine (A). In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by one or more amino acidsubstitutions in the amino acid sequence of any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822, such that amino acid residue 18is a cysteine (C). In some embodiments, the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byone or more amino acid substitutions in the amino acid sequence of anyone of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, suchthat amino acid residue 20 is an alanine (A), leucine (L), orphenylalanine (F). In some embodiments, the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byone or more amino acid substitutions in the amino acid sequence of anyone of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822, suchthat amino acid residue 16 is an isoleucine. In some embodiments, theIL-2 polypeptide or functional fragment thereof comprises an amino acidsequence produced by one or more amino acid substitutions in the aminoacid sequence of any one of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792,and 813-822, such that amino acid residue 29 is a leucine (L).

In some embodiments, the IL-2 peptide or functional fragment thereofcomprises an amino acid sequence produced by introducing one or more ofthe following amino acid substitutions into any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822: L18C, D20A, D20L, D20F, H161,N29L, L80F, R81D, L85V, I86V, I92F, C125S, C125G, and C125A.

In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence having one or more amino acidsubstitutions compared to the amino acid sequence of wildtype IL-2 thatreduces the affinity of the IL-2 peptide or functional fragment thereoffor IL-2Rα (CD25), and one or more amino acid substitutions compared tothe amino acid sequence of wildtype IL-2 that enhances the affinity ofthe IL-2 polypeptide or functional fragment thereof for IL-2R13 (CD122).In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by one or more amino acidsubstitutions in the amino acid sequence of any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822, such that one or more of aminoacid residues 38, 42, 45, and 62 is an alanine (A), amino acid residue42 is lysine (K), amino acid residue 72 is glycine (G), amino acidresidue 80 is phenylalanine (F), amino acid residue 81 is aspartic acid(D), amino acid residue 85 is valine (V), amino acid residue 86 isvaline (V), or amino acid residue 92 is phenylalanine (F), orcombinations thereof. As such, in some embodiments, the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence thatcomprises one or more of the following amino acid substitutions comparedto the mature form of wildtype IL-2: D20A, D20L, D20F, H161, L18C, N29L,R38A, F42A, F42E, F42K, K43A, Y45A, Y45N, Y45R, E62A, E62R, E62S, L72G,L80F, R81D, L85V, I86V, I92F, C125S, C125G, and C125A.

In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by one or more amino acidsubstitutions in the amino acid sequence of any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822, such that amino acid residue 38is a glycine (G), alanine (A), lysine (K), or tryptophan (W), amino acidresidue 42 is an alanine (A), lysine (K), or isoleucine (I), amino acidresidue 45 is an alanine (A) or asparagine (N), amino acid residue 62 isan alanine (A) or a leucine (L), or amino acid residue 68 is a valine(V), or combinations thereof. In some embodiments, the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby one or more amino acid substitutions in the amino acid sequence ofany one of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822,such that amino acid residue 38 is a lysine (K), amino acid residue 42is a glutamine (Q), amino acid residue 45 is a glutamic acid (E), oramino acid residue 68 is a valine (V), or combinations thereof. In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by one or more amino acidsubstitutions in the amino acid sequence of any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822, such that amino acid residue 38is an alanine (A), amino acid residue 42 is an isoleucine (I), aminoacid residue 45 is an asparagine (N), amino acid residue 62 is a leucine(L), or amino acid residue 68 is a valine (V), or combinations thereof.In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by one or more amino acidsubstitutions in the amino acid sequence of any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822, such that amino acid residue 38is a lysine (K), amino acid residue 42 is a lysine (K), amino acidresidue 45 is an arginine (R), amino acid residue 62 is a leucine (L),or amino acid residue 68 is a valine (V), or combinations thereof. Insome embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by one or more amino acidsubstitutions in the amino acid sequence of any one of SEQ ID NOs: 1-8,160, 243-251, 260, 775-792, and 813-822, such that amino acid residue 38is an alanine (A) or lysine (K), amino acid residue 42 is an alanine(A), amino acid residue 45 is an alanine (A), or amino acid residue 62is an alanine (A), or combinations thereof. In some embodiments, theIL-2 polypeptide or functional fragment thereof comprises an amino acidsequence produced by one or more amino acid substitutions in the aminoacid sequence of any one of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792,and 813-822, such that amino acid residue 42 is an isoleucine (I), aminoacid residue 45 is a glutamic acid (E), or amino acid residue 68 is avaline (V), or combinations thereof.

In some embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by introducing, or furtherintroducing, a C125S, C125G, or C125A substitution into any one of theamino acid sequences for an IL-2 polypeptide or functional fragmentthereof described herein.

In some embodiments, one or more amino acid residues are removed fromthe amino acid sequence of the IL-2 polypeptide or functional fragmentthereof for the purpose of removing an 0-glycosylation site. In someembodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by deleting the first threeamino acid residues (residues 1-3) of the amino acid sequence of any ofthe IL-2 polypeptides or functional fragments thereof disclosed herein.In some embodiments, one or more amino acid residues are substitutedinto the amino acid sequence of the IL-2 polypeptide or functionalfragment thereof for the purpose of removing an O-glycosylation site. Insome embodiments, the IL-2 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by introducing amino acidsubstitutions into one or more of the first three amino acid residues(residues 1-3) of the amino acid sequence of any of the IL-2polypeptides or functional fragments thereof disclosed herein.

The IL-2 polypeptide or functional fragment thereof comprises anamino-terminus and a carboxy-terminus. In some embodiments, a half-lifeextension domain is linked to the amino-terminus or the carboxy-terminusof the IL-2 polypeptide or functional fragment thereof. In someembodiments, a masking moiety is linked to the amino-terminus or thecarboxy-terminus of the IL-2 polypeptide or functional fragment thereof.In some embodiments, a linker is linked to the amino-terminus or thecarboxy-terminus of the IL-2 polypeptide or functional fragment thereof.In some embodiments, a cleavable peptide of a linker is linked to theamino-terminus or the carboxy-terminus of the IL-2 polypeptide orfunctional fragment thereof. In some embodiments, an N-terminal spacerdomain or a C-terminal spacer domain of a linker is linked to theamino-terminus or the carboxy-terminus of the IL-2 polypeptide orfunctional fragment thereof.

2. IL-15 Polypeptides

In some embodiments, the cytokine or functional fragment thereof is anIL-15 polypeptide or functional fragment thereof. In eukaryotic cells,IL-15 is synthesized as a precursor polypeptide of 162 amino acids,which is then processed into mature IL-15 by the removal of amino acidresidues 1-48. This results in a mature form of IL-15 consisting of 114amino acids (amino acid residues 49-162) that is secreted in a mature,active form (see SEQ ID NO: 167).

In some embodiments, the IL-15 polypeptide or functional fragmentthereof is any naturally occurring interleukin-15 (IL-15) protein ormodified variant thereof capable of binding to, or otherwise exhibitingaffinity for, an interleukin-15 receptor (IL-15R) or component thereof(e.g., the IL-15Rα, IL-2Rβ, and/or IL-2Rγ chain). In some embodiments,the IL-15 polypeptide or functional fragment thereof is a mature form ofIL-15 that consists of amino acid residues 49-162 of SEQ ID NO: 166. Insome embodiments, the IL-15 polypeptide or functional fragment thereofcomprises the amino acid sequence of SEQ ID NO: 167. In someembodiments, the IL-15 polypeptide or functional fragment thereofcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 166 or 167.

In some embodiments, the IL-15 polypeptide or functional fragmentthereof comprises an amino acid sequence produced by at least one aminoacid modification to the amino acid sequence of SEQ ID NO: 167. Each ofthe at least one amino acid modifications can be any amino acidmodification, such as a substitution, insertion, or deletion. In someembodiments, the IL-15 polypeptide or functional fragment thereofcomprises an amino acid sequence produced by at least 1, at least 2, atleast 3, at least 4, at least 5, at least 6, at least 7, at least 8, atleast 9, or at least 10 amino acid substitutions in the amino acidsequence of SEQ ID NO: 167.

The IL-15 polypeptide or functional fragment thereof comprises anamino-terminus and a carboxy-terminus. In some embodiments, a half-lifeextension domain is linked to the amino-terminus or the carboxy-terminusof the IL-15 polypeptide or functional fragment thereof. In someembodiments, a masking moiety is linked to the amino-terminus or thecarboxy-terminus of the IL-15 polypeptide or functional fragmentthereof. In some embodiments, a linker is linked to the amino-terminusor the carboxy-terminus of the IL-15 polypeptide or functional fragmentthereof. In some embodiments, a cleavable peptide of a linker is linkedto the amino-terminus or the carboxy-terminus of the IL-15 polypeptideor functional fragment thereof. In some embodiments, an N-terminalspacer domain or a C-terminal spacer domain of a linker is linked to theamino-terminus or the carboxy-terminus of the IL-15 polypeptide orfunctional fragment thereof.

B. Masking Moieties

A masking moiety as provided herein refers to a moiety capable ofbinding to, or otherwise exhibiting an affinity for, a cytokine orfunctional fragment thereof such that, in some embodiments, the bindingdecreases the affinity of the cytokine or functional fragment thereoffor its cognate receptor or protein. For example, a masking moiety foran IL-2 polypeptide or functional fragment thereof is capable of bindingto, or otherwise exhibiting an affinity for, an IL-2 polypeptide orfunctional fragment thereof such that, in some embodiments, the bindingdecreases the affinity of the IL-2 polypeptide or functional fragmentthereof for its cognate receptor or protein (e.g., IL-2R or a componentthereof, such as the IL-2Rα and/or IL-2Rβ chain). When bound to thecytokine or functional fragment thereof, the masking moiety blocks,occludes, inhibits (e.g. decreases) or otherwise prevents (e.g., masks)the activity or binding of the cytokine or functional fragment thereofto its cognate receptor or protein. In some embodiments that include afirst masking moiety and a second masking moiety, the presence of one ofthe masking moieties (e.g., the first masking moiety) blocks, occludes,inhibits (e.g. decreases) or otherwise prevents (e.g., masks) theactivity or binding of the cytokine or functional fragment thereof toits cognate receptor or protein, while the other masking moiety (e.g.,the second masking moiety) can, in some embodiments, remain associatedwith the cytokine or functional fragment thereof following cleavage ofthe first masking moiety and still allow, or possibly even promote,binding of the cytokine or functional fragment thereof to its cognatereceptor or protein at the site where the first masking moiety wasbound. See, e.g., FIG. 7B. Methods for determining the extent of bindingof a protein (e.g., cytokine) to a cognate protein (e.g., cytokinereceptor), is well known in the art.

The masked cytokines provided herein comprise a masking moiety. Themasking moiety comprises an amino-terminus and a carboxy-terminus. Insome embodiments, the masked cytokine comprises a single masking moiety.In some embodiments, the masked cytokine comprises more than one maskingmoiety, each of which can be any of the masking moieties describedherein. In some embodiments, the masked cytokine comprises a firstmasking moiety and a second masking moiety. It is understood, forinstance, that reference to “a masking moiety” or “the masking moiety”can refer to the masking moiety in a masked cytokine comprising a singlemasking moiety, or it can refer to the first masking moiety in a maskedcytokine comprising a first masking moiety and a second masking moiety,or it can refer to the second masking moiety in a masked cytokinecomprising a first masking moiety and a second masking moiety, or it canrefer to the first masking moiety and the second masking moiety in amasked cytokine comprising a first masking moiety and a second maskingmoiety.

In some embodiments, the masking moiety is linked to the cytokine orfunctional fragment thereof. In some embodiments, the masking moiety islinked to the cytokine or functional fragment thereof via a firstlinker. In some embodiments, the masked cytokine comprises a half-lifeextension domain that is linked to the masking moiety. In someembodiments, the masked cytokine comprises a half-life extension domainthat is linked to the masking moiety via a second linker. In someembodiments, the masking moiety is linked to the cytokine or functionalfragment thereof, and is linked to the half-life extension domain. Insome embodiments, the cytokine or functional fragment thereof is linkedto the amino-terminus of the masking peptide, and the half-lifeextension domain is linked to the carboxy-terminus of the maskingpeptide. In some embodiments, the cytokine or functional fragmentthereof is linked to the carboxy-terminus of the masking peptide, andthe half-life extension domain is linked to the amino-terminus of themasking peptide. In some embodiments, the half-life extension domain islinked to the amino-terminus or the carboxy-terminus of the maskingmoiety. In some embodiments, the second linker is linked to theamino-terminus or the carboxy-terminus of the masking moiety. In someembodiments, the masking moiety is linked to the first linker, and islinked to the second linker. In some embodiments, the first linker islinked to the amino-terminus of the masking peptide, and the secondlinker is linked to the carboxy-terminus of the masking peptide. In someembodiments, the first linker is linked to the carboxy-terminus of themasking peptide, and the second linker is linked to the amino-terminusof the masking peptide.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the first masking moiety is linked to the cytokine orfunctional fragment thereof, and the second masking moiety is linked tothe cytokine or functional fragment thereof. In some embodimentscomprising a first masking moiety and a second masking moiety, the firstmasking moiety is linked to the cytokine or functional fragment thereofvia a first linker, and the second masking moiety is linked to thecytokine or functional fragment thereof via a second linker. In someembodiments, the masked cytokine comprises a half-life extension domainthat is linked to either the first masking moiety or the second maskingmoiety. In some embodiments, the masked cytokine comprises a half-lifeextension domain that is linked to either the first masking moiety orthe second masking moiety via a third linker. In some embodiments, thefirst linker is linked to the amino-terminus or the carboxy-terminus ofthe first masking moiety. In some embodiments, the second linker islinked to the amino-terminus or the carboxy-terminus of the secondmasking moiety. In some embodiments, the half-life extension domain islinked to the amino-terminus or the carboxy-terminus of the firstmasking moiety. In some embodiments, the half-life extension domain islinked to the amino-terminus or the carboxy-terminus of the secondmasking moiety. In some embodiments, the third linker is linked to theamino-terminus or the carboxy-terminus of the first masking moiety. Insome embodiments, the third linker is linked to the amino-terminus orthe carboxy-terminus of the second masking moiety.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the first masking moiety is linked to the firsthalf-life extension domain, the second masking moiety is linked to thefirst masking moiety, and the cytokine or functional fragment thereof islinked to the second half-life extension domain. In some embodimentscomprising a first masking moiety and a second masking moiety, the firstmasking moiety is linked to the first half-life extension domain via afirst linker, the second masking moiety is linked to the first maskingmoiety via a second linker, and the cytokine or functional fragmentthereof is linked to the second half-life extension domain via a thirdlinker. In some embodiments, the first linker is linked to theamino-terminus or the carboxy-terminus of the first half-life extensiondomain. In some embodiments, the second linker is linked to theamino-terminus or the carboxy-terminus of the second masking moiety. Insome embodiments, the second half-life extension domain is linked to theamino-terminus or the carboxy-terminus of the cytokine or functionalfragment thereof. In some embodiments, the first half-life extensiondomain is linked to the amino-terminus or the carboxy-terminus of thefirst masking moiety. In some embodiments, the third linker is linked tothe amino-terminus or the carboxy-terminus of the second half-lifeextension domain. In some embodiments, the third linker is linked to theamino-terminus or the carboxy-terminus of the cytokine or functionalfragment thereof.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the second masking moiety is linked to the firsthalf-life extension domain, the first masking moiety is linked to thesecond masking moiety, and the cytokine or functional fragment thereofis linked to the second half-life extension domain. In some embodimentscomprising a first masking moiety and a second masking moiety, thesecond masking moiety is linked to the first half-life extension domainvia a first linker, the first masking moiety is linked to the secondmasking moiety via a second linker, and the cytokine or functionalfragment thereof is linked to the second half-life extension domain viaa third linker. In some embodiments, the first linker is linked to theamino-terminus or the carboxy-terminus of the first half-life extensiondomain. In some embodiments, the second linker is linked to theamino-terminus or the carboxy-terminus of the first masking moiety. Insome embodiments, the second half-life extension domain is linked to theamino-terminus or the carboxy-terminus of the cytokine or functionalfragment thereof. In some embodiments, the first half-life extensiondomain is linked to the amino-terminus or the carboxy-terminus of thesecond masking moiety. In some embodiments, the third linker is linkedto the amino-terminus or the carboxy-terminus of the second half-lifeextension domain. In some embodiments, the third linker is linked to theamino-terminus or the carboxy-terminus of the cytokine or functionalfragment thereof.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the masking moiety is linked to thefirst half-life extension domain. In some embodiments, the firsthalf-life extension domain is linked to the amino-terminus or thecarboxy-terminus of the masking moiety. In some embodiments, the maskingmoiety is linked to the first half-life extension domain via a firstlinker. In some embodiments, the first linker is linked to theamino-terminus or the carboxy-terminus of the masking moiety.

In some embodiments comprising a first half-life extension domain, asecond half-life extension domain, a first masking moiety, and a secondmasking moiety, the first masking moiety is linked to the firsthalf-life extension domain and the second masking moiety is linked tothe cytokine or functional fragment thereof. In some embodiments, thesecond masking moiety is further linked to the second half-lifeextension domain. In some embodiments, the first masking moiety islinked to the first half-life extension domain via a first linker,and/or either the second masking moiety or the cytokine or functionalfragment thereof is linked to the second half-life extension domain viaa second linker. In some embodiments, the second masking moiety islinked to the cytokine or functional fragment thereof via a thirdlinker.

In some embodiments, the first half-life extension domain is linked tothe amino-terminus or the carboxy-terminus of the first masking moiety.In some embodiments, the cytokine or functional fragment thereof islinked to the amino-terminus or the carboxy-terminus of the secondmasking moiety. In some embodiments, the first linker is linked to theamino-terminus or the carboxy-terminus of the first masking moiety. Insome embodiments, the second linker is linked to the amino-terminus orthe carboxy-terminus of the second masking moiety. In some embodiments,the third linker is linked to the amino-terminus or the carboxy-terminusof the second masking moiety. In some embodiments, the second linker islinked to the amino-terminus of the second masking moiety and the thirdlinker is linked to the carboxy-terminus of the second masking moiety.In some embodiments, the second linker is linked to the carboxy-terminusof the second masking moiety and the third linker is linked to theamino-terminus of the second masking moiety.

In some embodiments, the masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 9, 10, 161-165,187-218, 221-229, 231, and 261. In some embodiments, the masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 9, 10, 161-165, 187-218, 221-229, 231, and261. In some embodiments, the masking moiety comprises the amino acidsequence of SEQ ID NO: 261. In some embodiments, the masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 261.

In some embodiments, the masked cytokine comprises a first maskingmoiety and a second masking moiety. In some embodiments, the firstmasking moiety comprises the amino acid sequence of SEQ ID NO: 9 or 231,and the second masking moiety comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 10, 161-165, 187-218, 221-229,and 261. In some embodiments, the first masking moiety comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 9 or 231, and thesecond masking moiety comprises an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 10, 161-165, 187-218,221-229, and 261. In some embodiments, the first masking moietycomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 10, 161-165, 187-218, 221-229, and 261, and the secondmasking moiety comprises the amino acid sequence of SEQ ID NO: 9 or 231.In some embodiments, the first masking moiety comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:10, 161-165, 187-218, 221-229, and 261, and the second masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 9 or 231. Insome embodiments, the first masking moiety comprises the amino acidsequence of SEQ ID NO: 9 or 231, and the second masking moiety comprisesthe amino acid sequence of SEQ ID NO: 261. In some embodiments, thesecond masking moiety comprises the amino acid sequence of SEQ ID NO: 9or 231, and the first masking moiety comprises the amino acid sequenceof SEQ ID NO: 261. In some embodiments, the first masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 261, and thesecond masking moiety comprises an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to the amino acid sequence ofSEQ ID NO: 9 or 231. In some embodiments, the second masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 261, and thefirst masking moiety comprises an amino acid sequence having about or atleast about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, or 99% sequence identity to the amino acid sequence of SEQ IDNO: 9 or 231.

In some embodiments, the first masking moiety comprises the amino acidsequence of SEQ ID NO: 9 or 231, and the second masking moiety comprisesan amino acid sequence selected from the group consisting of SEQ ID NOs:10, 161-165, 221-226, and 261. In some embodiments, the first maskingmoiety comprises an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to the amino acid sequence of SEQ ID NO: 9 or 231,and the second masking moiety comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 10, 161-165,221-226, and 261. In some embodiments, the first masking moietycomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 10, 161-165, 221-226, and 261, and the second masking moietycomprises the amino acid sequence of SEQ ID NO: 9 or 231. In someembodiments, the first masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 10, 161-165,221-226, and 261, and the second masking moiety comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 9 or 231. In some embodiments, thefirst masking moiety comprises the amino acid sequence of SEQ ID NO: 9or 231, and the second masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 10, 161-165, 221-226,261, 826, and 827. In some embodiments, the first masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 9 or 231, andthe second masking moiety comprises an amino acid sequence having aboutor at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 10, 161-165, 221-226,261, 826, and 827. In some embodiments, the second masking moietycomprises the amino acid sequence of SEQ ID NO: 9 or 231, and the firstmasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 221-226, 261, 826, and 827. Insome embodiments, the second masking moiety comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 9 or 231, and the first masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 221-226, 261, 826, and 827.

In some embodiments, the first masking moiety comprises the amino acidsequence of SEQ ID NO: 9 or 231, and the second masking moiety comprisesan amino acid sequence selected from the group consisting of SEQ ID NOs:187-218. In some embodiments, the first masking moiety comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 9 or 231, and thesecond masking moiety comprises an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 187-218. In someembodiments, the first masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 187-218, and thesecond masking moiety comprises the amino acid sequence of SEQ ID NO: 9or 231. In some embodiments, the first masking moiety comprises an aminoacid sequence having about or at least about 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity toan amino acid sequence selected from the group consisting of SEQ ID NOs:187-218, and the second masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 9 or 231.

In some embodiments, the first masking moiety comprises the amino acidsequence of SEQ ID NO: 9 or 231, and the second masking moiety comprisesan amino acid sequence selected from the group consisting of SEQ ID NOs:227-229. In some embodiments, the first masking moiety comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 9 or 231, and thesecond masking moiety comprises an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 227-229. In someembodiments, the first masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 227-229, and thesecond masking moiety comprises the amino acid sequence of SEQ ID NO: 9or 231. In some embodiments, the first masking moiety comprises an aminoacid sequence having about or at least about 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity toan amino acid sequence selected from the group consisting of SEQ ID NOs:227-229, and the second masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 9 or 231.

In some embodiments, the first masking moiety comprises the amino acidsequence of SEQ ID NO: 9, and the second masking moiety comprises theamino acid sequence of SEQ ID NO: 10. In some embodiments, the firstmasking moiety comprises the amino acid sequence of SEQ ID NO: 10, andthe second masking moiety comprises the amino acid sequence of SEQ IDNO: 9. In some embodiments, the first masking moiety comprises an aminoacid sequence having about or at least about 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity tothe amino acid sequence of SEQ ID NO: 9, and the second masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 10. In someembodiments, the first masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 10, and the second masking moiety comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 9. In someembodiments, the masking moiety comprises an amino acid sequenceproduced by one or more of the following amino acid substitutions to SEQID NO: 10 or 261: C122S, C168S, R42A, K71A, T73A, T74A, V75A, H133A,Y134A, R137D, Q162W, E170A, and Q188A. In some embodiments, the maskingmoiety comprising an amino acid sequence that is produced by one or moreamino acid substitutions comprises the amino acid sequence of SEQ ID NO:826.

In some embodiments, the masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 10, 161-165, 219-229,232-234, 261, and 823-825. In some embodiments, the masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 219-229, 232-234, 261, and823-825. In some embodiments, the masking moiety comprises the aminoacid sequence of SEQ ID NO: 261. In some embodiments, the masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 261. In someembodiments, the masking moiety comprises the amino acid sequence of SEQID NO: 826 or 827, or comprises an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to the amino acid sequence ofSEQ ID NO: 826 or 827.

In some embodiments, the masked cytokine comprises a first maskingmoiety and a second masking moiety. In some embodiments, the firstmasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 232-234, and 823-825, and the second maskingmoiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 219-229, and 261. In someembodiments, the first masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 10, 161-165, 219-229,and 261, and the second masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 232-234, and 823-825.In some embodiments, the first masking moiety comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:10, 161-165, 219-229, and 261, and the second masking moiety comprisesan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to an amino acid sequence selected from the group consisting ofSEQ ID NOs: 232-234, and 823-825. In some embodiments, the secondmasking moiety comprises an amino acid sequence having about or at leastabout 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, or 99% sequence identity to an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 10, 161-165, 219-229, and 261, andthe first masking moiety comprises an amino acid sequence having aboutor at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 232-234, and 823-825.

In some embodiments, the first masking moiety comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825, and the second masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 10, 161-165, 219-229,261, 826, and 827. In some embodiments, the second masking moietycomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 232-234, and 823-825, and the first masking moiety comprisesan amino acid sequence selected from the group consisting of SEQ ID NOs:10, 161-165, 219-229, 261, 826, and 827. In some embodiments, the firstmasking moiety comprises an amino acid sequence having about or at leastabout 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, or 99% sequence identity to an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 10, 161-165, 219-229, 261, 826, and827, and the second masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825. In some embodiments, the second masking moiety comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to an amino acid sequence selected from the group consisting ofSEQ ID NOs: 10, 161-165, 219-229, 261, 826, and 827, and the firstmasking moiety comprises an amino acid sequence having about or at leastabout 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, or 99% sequence identity to an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 232-234, and 823-825. In someembodiments, the first masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 232-234, and 823-825,and the second masking moiety comprises the amino acid sequence of SEQID NO: 826 or 827. In some embodiments, the second masking moietycomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 232-234, and 823-825, and the first masking moiety comprisesthe amino acid sequence of SEQ ID NO: 826 or 827.

In some embodiments, the first masking moiety comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825, and the second masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 10, 161-165, 221-226,and 261. In some embodiments, the first masking moiety comprises anamino acid sequence selected from the group consisting of SEQ ID NOs:10, 161-165, 221-226, and 261, and the second masking moiety comprisesan amino acid sequence selected from the group consisting of SEQ ID NOs:232-234, and 823-825. In some embodiments, the first masking moietycomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 221-226, and 261, and the secondmasking moiety comprises an amino acid sequence having about or at leastabout 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%,98%, or 99% sequence identity to an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 232-234, and 823-825. In someembodiments, the second masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 10, 161-165,221-226, and 261, and the first masking moiety comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:232-234, and 823-825.

In some embodiments, the first masking moiety comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825, and the second masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 227-229. In someembodiments, the first masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 227-229, and thesecond masking moiety comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 232-234, and 823-825. In someembodiments, the first masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 227-229, andthe second masking moiety comprises an amino acid sequence having aboutor at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 232-234, and 823-825.In some embodiments, the second masking moiety comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:227-229, and the first masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825.

In some embodiments, the first masking moiety comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825, and the second masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 219 and 220. In someembodiments, the first masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 219 and 220, and thesecond masking moiety comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 232-234, and 823-825. In someembodiments, the first masking moiety comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 219 and 220,and the second masking moiety comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825. In some embodiments, the second masking moiety comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to an amino acid sequence selected from the group consisting ofSEQ ID NOs: 219 and 220, and the first masking moiety comprises an aminoacid sequence having about or at least about 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity toan amino acid sequence selected from the group consisting of SEQ ID NOs:232-234, and 823-825.

In some embodiments, the masking moiety comprises an amino acid sequenceproduced by introducing one or more of the following amino acidsubstitutions into the amino acid sequence of any one of SEQ ID NOs:232-234, and 823-825: R24A, R26A, K34A, 540A, L42A, and P67A. In someembodiments, the masking moiety comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825 and is further modified by introducing one or more of thefollowing amino acid substitutions into the amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825: R24A, R26A, K34A, 540A, L42A, and P67A.

In some embodiments, the masking moiety comprises IL-2Rα (also referredto as CD25) or a fragment, portion, or variant thereof that retains orotherwise demonstrates an affinity to IL-2. In some embodiments, themasking moiety comprises IL-2Rα (also referred to as CD25) or afragment, portion, or variant thereof and comprises the amino acidsequence of SEQ ID NO: 9 or 231. In some embodiments, the masking moietycomprises IL-2Rβ (also referred to as CD122) or a fragment, portion, orvariant thereof that retains or otherwise demonstrates an affinity toIL-2 and/or IL-15. In some embodiments, the masking moiety comprisesIL-2Rβ (also referred to as CD122) or a fragment, portion, or variantthereof and comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 221-226, 261, 826, and 827. Insome embodiments, the masking moiety comprises IL-2Rγ (also referred toas CD132) or a fragment, portion, or variant thereof that retains orotherwise demonstrates an affinity to IL-2 and/or IL-15. In someembodiments, the masking moiety comprises IL-15Rα (also referred to asCD215) or a fragment, portion, or variant thereof that retains orotherwise demonstrates an affinity to IL-15. In some embodiments, themasking moiety comprises IL-15Rα (also referred to as CD215) or afragment, portion, or variant thereof and comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 232-234, and823-825. In some embodiments, the masking moiety comprises anantigen-binding domain of an antibody or fragment thereof. In someembodiments, the masking moiety comprises an antigen-binding domain ofan anti-IL-2 antibody or fragment thereof. In some embodiments, themasking moiety comprises an antigen-binding domain of an anti-IL-15antibody or fragment thereof.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the first masking moiety comprises IL-2Rα or a fragment,portion, or variant thereof that retains or otherwise demonstrates anaffinity to IL-2, and the second masking moiety comprises IL-2Rβ or afragment, portion, or variant thereof that retains or otherwisedemonstrates an affinity to IL-2. In some embodiments comprising a firstmasking moiety and a second masking moiety, the first masking moietycomprises IL-2Rβ or a fragment, portion, or variant thereof that retainsor otherwise demonstrates an affinity to IL-2, and the second maskingmoiety comprises IL-2Rα or a fragment, portion, or variant thereof thatretains or otherwise demonstrates an affinity to IL-2. In someembodiments comprising a first masking moiety and a second maskingmoiety, the first masking moiety comprises IL-2Rα or a fragment,portion, or variant thereof that retains or otherwise demonstrates anaffinity to IL-2, and the second masking moiety comprises IL-2Rγ or afragment, portion, or variant thereof that retains or otherwisedemonstrates an affinity to IL-2. In some embodiments comprising a firstmasking moiety and a second masking moiety, the first masking moietycomprises IL-2Rγ or a fragment, portion, or variant thereof that retainsor otherwise demonstrates an affinity to IL-2, and the second maskingmoiety comprises IL-2Rα or a fragment, portion, or variant thereof thatretains or otherwise demonstrates an affinity to IL-2. In someembodiments comprising a first masking moiety and a second maskingmoiety, the first masking moiety comprises IL-2Rα or a fragment,portion, or variant thereof that retains or otherwise demonstrates anaffinity to IL-2, and the second masking moiety comprises anantigen-binding domain of an anti-IL-2 antibody or fragment thereof. Insome embodiments comprising a first masking moiety and a second maskingmoiety, the first masking moiety comprises an antigen-binding domain ofan anti-IL-2 antibody or fragment thereof, and the second masking moietycomprises IL-2Rα or a fragment, portion, or variant thereof that retainsor otherwise demonstrates an affinity to IL-2.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the first masking moiety comprises IL-15Rα or afragment, portion, or variant thereof that retains or otherwisedemonstrates an affinity to IL-15, and the second masking moietycomprises IL-2Rβ or a fragment, portion, or variant thereof that retainsor otherwise demonstrates an affinity to IL-15. In some embodimentscomprising a first masking moiety and a second masking moiety, the firstmasking moiety comprises IL-2Rβ or a fragment, portion, or variantthereof that retains or otherwise demonstrates an affinity to IL-15, andthe second masking moiety comprises IL-15Rα or a fragment, portion, orvariant thereof that retains or otherwise demonstrates an affinity toIL-15. In some embodiments comprising a first masking moiety and asecond masking moiety, the first masking moiety comprises IL-15Rα or afragment, portion, or variant thereof that retains or otherwisedemonstrates an affinity to IL-15, and the second masking moietycomprises IL-2Rγ or a fragment, portion, or variant thereof that retainsor otherwise demonstrates an affinity to IL-15. In some embodimentscomprising a first masking moiety and a second masking moiety, the firstmasking moiety comprises IL-2Rγ or a fragment, portion, or variantthereof that retains or otherwise demonstrates an affinity to IL-15, andthe second masking moiety comprises IL-15Rα or a fragment, portion, orvariant thereof that retains or otherwise demonstrates an affinity toIL-15. In some embodiments comprising a first masking moiety and asecond masking moiety, the first masking moiety comprises IL-15Rα or afragment, portion, or variant thereof that retains or otherwisedemonstrates an affinity to IL-15, and the second masking moietycomprises an antigen-binding domain of an anti-IL-15 antibody orfragment thereof. In some embodiments comprising a first masking moietyand a second masking moiety, the first masking moiety comprises anantigen-binding domain of an anti-IL-15 antibody or fragment thereof,and the second masking moiety comprises IL-15Rα or a fragment, portion,or variant thereof that retains or otherwise demonstrates an affinity toIL-15.

C. Linkers

A linker as provided herein refers to a peptide of two more amino acidsthat is used to link two components together, such as two components ofany of the masked cytokines described herein. In some embodiments, thelinker comprises a cleavable peptide. In some embodiments, the linkercomprises an amino-terminal spacer domain (N-terminal spacer domain)and/or a carboxy-terminal spacer domain (C-terminal spacer domain) Insome embodiments, the linker comprises an N-terminal spacer domain, acleavable peptide, and/or a C-terminal spacer domain. In someembodiments, the linker consists of an N-terminal spacer domain. In someembodiments, the linker consists of a C-terminal spacer domain. In someembodiments, the linker consists of an N-terminal spacer domain and aC-terminal spacer domain. In some embodiments, the linker consists of acleavable peptide. In some embodiments, the linker consists of anN-terminal spacer domain, a cleavable peptide, and a C-terminal spacerdomain. In some embodiments, the linker consists of an N-terminal spacerdomain and a cleavable peptide. In some embodiments, the linker consistsof a cleavable peptide and a C-terminal spacer domain. In someembodiments, the linker consists of a cleavable peptide.

In some embodiments, the masked cytokine comprises a linker. In someembodiments, the masked cytokine comprises a single linker. In someembodiments, the masked cytokine comprises more than one linker, each ofwhich can be any of the linkers described herein. In some embodiments,the masked cytokine comprises a first linker and a second linker. Insome embodiments, the masked cytokine comprises a first linker, a secondlinker, and a third linker. In some embodiments, the masked cytokinecomprises a first linker, a second linker, a third linker, and a fourthlinker. For example, reference to “a linker” or “the linker” can referto the linker in a masked cytokine comprising a single linker, or it canrefer to the first linker in a masked cytokine comprising a first linkerand a second linker, or it can refer to the second linker in a maskedcytokine comprising a first linker and a second linker, or it can referto the first linker and the second linker in a masked cytokinecomprising a first linker and a second linker, or it can refer to thefirst linker, the second linker, and/or the third linker in a maskedcytokine comprising a first linker, a second linker, and a third linker,or it can refer to the first linker, the second linker, the thirdlinker, and/or the fourth linker in a masked cytokine comprising a firstlinker, a second linker, a third linker, and a fourth linker.

It is understood that each of the following terms are considered a“linker” as described herein: a linker, a first linker, a second linker,a third linker, and a fourth linker, as well as any other numberedlinker (e.g., a fifth linker, a sixth linker, etc.). As such, in someembodiments, the masked cytokine may comprise a linker, a first linker,a second linker, a third linker, and/or a fourth linker, each of whichis considered “a linker” as described herein, and any of the linkersdescribed herein may be a linker, a first linker, a second linker, athird linker, and/or a fourth linker as described herein.

It is also understood that two components “linked” together includesembodiments in which the two components are directly linked together aswell as embodiments in which the two components are linked together viaa linker as described herein. For example, “a half-life extension domainthat is linked to the masking moiety” is interpreted to mean either thatthe amino acid sequence of the half-life extension domain is linkeddirectly to the amino acid sequence of the masking moiety, or that theamino acid sequence of the half-life extension domain is linked to theamino acid sequence of the masking moiety via a linker, such as any ofthe linkers described herein.

The linker comprises an amino-terminus and a carboxy-terminus. In someembodiments, a masking moiety is linked to the amino-terminus or thecarboxy-terminus of the linker. In some embodiments, a cytokine orfunctional fragment thereof is linked to the amino-terminus or thecarboxy-terminus of the linker. In some embodiments, a cytokine orfunctional fragment thereof is linked to the amino-terminus of thelinker, and a masking moiety is linked to the carboxy-terminus of thelinker. In some embodiments, a cytokine or functional fragment thereofis linked to the carboxy-terminus of the linker, and a masking moiety islinked to the amino-terminus of the linker. In some embodiments, ahalf-life extension domain is linked to the amino-terminus or thecarboxy-terminus of the linker. In some embodiments, a half-lifeextension domain is linked to the amino-terminus of the linker, and amasking moiety is linked to the carboxy-terminus of the linker. In someembodiments, a half-life extension domain is linked to thecarboxy-terminus of the linker, and a masking moiety is linked to theamino-terminus of the linker. In some embodiments, a half-life extensiondomain is linked to the amino-terminus of the linker, and a cytokine orfunctional fragment thereof is linked to the carboxy-terminus of thelinker. In some embodiments, a half-life extension domain is linked tothe carboxy-terminus of the linker, and a cytokine or functionalfragment thereof is linked to the amino-terminus of the linker.

In some embodiments comprising a first masking moiety and a secondmasking moiety that are each linked to a cytokine or functional fragmentthereof, the first masking moiety or the second masking moiety is linkedto the amino-terminus of a linker, and the cytokine or functionalfragment thereof is linked to the carboxy-terminus of the linker. Insome embodiments comprising a first masking moiety and a second maskingmoiety that are each linked to a cytokine or functional fragmentthereof, the first masking moiety or the second masking moiety is linkedto the carboxy-terminus of a linker, and the cytokine or functionalfragment thereof is linked to the amino-terminus of the linker.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, a masking moiety is linked to theamino-terminus of a linker, and either the first half-life extensiondomain or the second half-life extension domain is linked to thecarboxy-terminus of the linker. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, amasking moiety is linked to the carboxy-terminus of the linker, andeither the first half-life extension domain or the second half-lifeextension domain is linked to the amino-terminus of the linker. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, a cytokine or functional fragment thereof islinked to the amino-terminus of the linker, and either the firsthalf-life extension domain or the second half-life extension domain islinked to the carboxy-terminus of the linker. In some embodimentscomprising a first half-life extension domain and a second half-lifeextension domain, a cytokine or functional fragment thereof is linked tothe carboxy-terminus of the linker, and either the first half-lifeextension domain or the second half-life extension domain is linked tothe amino-terminus of the linker.

In some embodiments comprising a first masking moiety linked to a firsthalf-life extension domain, a second masking moiety linked to a cytokineor functional fragment thereof, and where either the second maskingmoiety or the cytokine or functional fragment thereof is linked to thesecond half-life extension domain, the first masking moiety is linked tothe amino-terminus of the linker and the first half-life extensiondomain is linked to the carboxy-terminus of the linker. In someembodiments comprising a first masking moiety linked to a firsthalf-life extension domain, a second masking moiety linked to a cytokineor functional fragment thereof, and where either the second maskingmoiety or the cytokine or functional fragment thereof is linked to thesecond half-life extension domain, the first masking moiety is linked tothe carboxy-terminus of the linker and the first half-life extensiondomain is linked to the amino-terminus of the linker. In someembodiments comprising a first masking moiety linked to a firsthalf-life extension domain, a second masking moiety linked to a cytokineor functional fragment thereof, and where either the second maskingmoiety or the cytokine or functional fragment thereof is linked to thesecond half-life extension domain, the second masking moiety is linkedto the amino-terminus of the linker and the cytokine or functionalfragment thereof is linked to the carboxy-terminus of the linker. Insome embodiments comprising a first masking moiety linked to a firsthalf-life extension domain, a second masking moiety linked to a cytokineor functional fragment thereof, and where either the second maskingmoiety or the cytokine or functional fragment thereof is linked to thesecond half-life extension domain, the second masking moiety is linkedto the carboxy-terminus of the linker and the cytokine or functionalfragment thereof is linked to the amino-terminus of the linker. In someembodiments comprising a first masking moiety linked to a firsthalf-life extension domain, a second masking moiety linked to a cytokineor functional fragment thereof, and where either the second maskingmoiety or the cytokine or functional fragment thereof is linked to thesecond half-life extension domain, the second masking moiety is linkedto the amino-terminus of the linker and the second half-life extensiondomain is linked to the carboxy-terminus of the linker. In someembodiments comprising a first masking moiety linked to a firsthalf-life extension domain, a second masking moiety linked to a cytokineor functional fragment thereof, and where either the second maskingmoiety or the cytokine or functional fragment thereof is linked to thesecond half-life extension domain, the second masking moiety is linkedto the carboxy-terminus of the linker and the second half-life extensiondomain is linked to the amino-terminus of the linker. In someembodiments comprising a first masking moiety linked to a firsthalf-life extension domain, a second masking moiety linked to a cytokineor functional fragment thereof, and where either the second maskingmoiety or the cytokine or functional fragment thereof is linked to thesecond half-life extension domain, the cytokine or functional fragmentthereof is linked to the amino-terminus of the linker and the secondhalf-life extension domain is linked to the carboxy-terminus of thelinker. In some embodiments comprising a first masking moiety linked toa first half-life extension domain, a second masking moiety linked to acytokine or functional fragment thereof, and where either the secondmasking moiety or the cytokine or functional fragment thereof is linkedto the second half-life extension domain, the cytokine or functionalfragment thereof is linked to the carboxy-terminus of the linker and thesecond half-life extension domain is linked to the amino-terminus of thelinker.

In some embodiments comprising a first masking moiety linked to a firsthalf-life extension domain via a first linker, a second masking moietylinked to the first masking moiety via second linker, and a cytokine orfunctional fragment thereof linked to a second half-life extensiondomain via a third linker, the first masking moiety is linked to thecarboxy-terminus of the first linker and the first half-life extensiondomain is linked to the amino-terminus of the first linker, the secondmasking moiety is linked to the carboxy-terminus of the second linkerand the first masking moiety is linked to the amino-terminus of thesecond linker, and the cytokine or functional fragment thereof is linkedto the carboxy-terminus of the third linker and the second half-lifeextension domain is linked to the amino-terminus of the third linker.

In some embodiments comprising a first masking moiety linked to a firsthalf-life extension domain via a first linker, a second masking moietylinked to the first masking moiety via second linker, and a cytokine orfunctional fragment thereof linked to a second half-life extensiondomain via a third linker, the first masking moiety is linked to theamino-terminus of the first linker and the first half-life extensiondomain is linked to the carboxy-terminus of the first linker, the secondmasking moiety is linked to the amino-terminus of the second linker andthe first masking moiety is linked to the carboxy-terminus of the secondlinker, and the cytokine or functional fragment thereof is linked to theamino-terminus of the third linker and the second half-life extensiondomain is linked to the carboxy-terminus of the third linker.

In some embodiments comprising a second masking moiety linked to a firsthalf-life extension domain via a first linker, a first masking moietylinked to the second masking moiety via second linker, and a cytokine orfunctional fragment thereof linked to a second half-life extensiondomain via a third linker, the second masking moiety is linked to thecarboxy-terminus of the first linker and the first half-life extensiondomain is linked to the amino-terminus of the first linker, the firstmasking moiety is linked to the carboxy-terminus of the second linkerand the second masking moiety is linked to the amino-terminus of thesecond linker, and the cytokine or functional fragment thereof is linkedto the carboxy-terminus of the third linker and the second half-lifeextension domain is linked to the amino-terminus of the third linker.

In some embodiments comprising a second masking moiety linked to a firsthalf-life extension domain via a first linker, a first masking moietylinked to the second masking moiety via second linker, and a cytokine orfunctional fragment thereof linked to a second half-life extensiondomain via a third linker, the second masking moiety is linked to theamino-terminus of the first linker and the first half-life extensiondomain is linked to the carboxy-terminus of the first linker, the firstmasking moiety is linked to the amino-terminus of the second linker andthe second masking moiety is linked to the carboxy-terminus of thesecond linker, and the cytokine or functional fragment thereof is linkedto the amino-terminus of the third linker and the second half-lifeextension domain is linked to the carboxy-terminus of the third linker.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domainis linked to the second half-life extension domain. In some embodimentscomprising a first half-life extension domain and a second half-lifeextension domain, the first half-life extension domain is linked to thesecond half-life extension domain via a linker.

In some embodiments, the linker comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 11-153, 235-242,262-264, 268-320, 323-338, 340-354, 356-555, 668, 691, 724, 725, 727,762-771, 794, and 797-812. In some embodiments, the linker comprises anamino acid sequence selected from the group consisting of SEQ ID NOs:20-153, 235-242, 264, 268-317, 323-338, 340-347, 356-415, 420-491,494-501, 504-535, 538-555, 727, 794, and 799. In some embodiments, thelinker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-19, 262, 263, 318-320, 348-354, 416-419,492, 493, 502, 503, 536, 537, 668, 691, 724, 725, 762-771, 797, 798, and800-812. In some embodiments, the linker comprises the amino acidsequence of SEQ ID NO: 262. In some embodiments, the linker comprisesthe amino acid sequence of SEQ ID NO: 28. In some embodiments, thelinker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-95, 235, 268, and 269. In some embodiments,the linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-33. In some embodiments, the linkercomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 34-44. In some embodiments, the linker comprises an aminoacid sequence selected from the group consisting of SEQ ID NOs: 45-95.In some embodiments, the linker comprises the amino acid sequence of SEQID NO: 235. In some embodiments, the linker comprises the amino acidsequence of SEQ ID NO: 28. In some embodiments, the linker comprises theamino acid sequence of SEQ ID NO: 268. In some embodiments, the linkercomprises the amino acid sequence of SEQ ID NO: 269. In someembodiments, the linker comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 263, 318-322, 339, 348-355, 416-419,492, 493, 502, 503, 536, 537, 668, 691, 724, 725, 727, 762-771, 794,795, and 797-812.

In some embodiments, the linker comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 794, 795, and 797-812.In some embodiments, the linker comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

In some embodiments, the linker comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 11-153,235-242, 262-264, 268-320, 323-338, 340-354, 356-555, 668, 691, 724,725, 727, 762-771, 794, and 797-812. In some embodiments, the linkercomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-19, 262, 263, 318-320, 348-354, 416-419,492, 493, 502, 503, 536, 537, 668, 691, 724, 725, 762-771, 797, 798, and800-812. In some embodiments, the linker comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:20-33. In some embodiments, the linker comprises an amino acid sequencehaving about or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%,93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 34-44. Insome embodiments, the linker comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 45-95. Insome embodiments, the linker comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 235. In some embodiments, the linker comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 262. In someembodiments, the linker comprises an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 263, 318-320, 348-354,416-419, 492, 493, 502, 503, 536, 537, 668, 691, 724, 725, 762-771, 797,798, and 800-812. In some embodiments, the linker comprises an aminoacid sequence having about or at least about 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity toan amino acid sequence selected from the group consisting of SEQ ID NOs:318-320. In some embodiments, the linker comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:348-354. In some embodiments, the linker comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:416-419. In some embodiments, the linker comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:492, 493, 502, 503, 536, 537. In some embodiments, the linker comprisesan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to an amino acid sequence selected from the group consisting ofSEQ ID NOs: 668, 691, 724, 725, 762-771, 797, 798, and 800-812. In someembodiments, the linker comprises an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to an amino acid sequenceselected from the group consisting of SEQ ID NOs: 762-771, 797, 798, and800-812. In some embodiments, the linker comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:762-771. In some embodiments, the linker comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:797, 798, and 800-812. In some embodiments, the linker comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to an amino acid sequence selected from the group consisting ofSEQ ID NOs: 800-812.

The cleavable peptides and spacer domains of some embodiments of thelinker are described in more detail below.

1. Cleavable Peptides

In some embodiments, the linker comprises a cleavable peptide. In someembodiments having more than one linker that comprises a cleavablepeptide, a cleavable peptide may be referred to as a first cleavablepeptide, a second cleavable peptide, or a third cleavable peptide, eachof which is considered “a cleavable peptide” and may be any of thecleavable peptides described herein. For example, reference to “acleavable peptide” or “the cleavable peptide” can refer to the cleavablepeptide in a masked cytokine comprising a single cleavable peptide, orit can refer to the first cleavable peptide in a masked cytokinecomprising a first cleavable peptide and a second cleavable peptide, orit can refer to the second cleavable peptide in a masked cytokinecomprising a first cleavable peptide and a second cleavable peptide, orit can refer to the first cleavable peptide and the second cleavablepeptide in a masked cytokine comprising a first cleavable peptide and asecond cleavable peptide, or it can refer to the first cleavablepeptide, the second cleavable peptide, and/or the third cleavablepeptide in a masked cytokine comprising a first cleavable peptide, asecond cleavable peptide, and a third cleavable peptide. It isconceivable that, in some embodiments, more than three cleavablepeptides may be present in accordance with the teachings herein.

A cleavable peptide is a polypeptide that includes a cleavage site, suchas a protease cleavage site. In some embodiments, the cleavable peptidecomprises more than one cleavage site. A “cleavage site” as used hereinrefers to a recognizable site for cleavage of a portion of the cleavablepeptide found in any of the linkers that comprise a cleavable peptidedescribed herein. Thus, a cleavage site may be found in the sequence ofa cleavable peptide as described herein. In some embodiments, thecleavage site is an amino acid sequence that is recognized and cleavedby a cleaving agent. Exemplary cleaving agents include proteins,enzymes, DNAzymes, RNAzymes, metals, acids, and bases.

In some embodiments, the cleavable peptide comprises a protease cleavagesite. In some embodiments, the protease cleavage site is atumor-associated protease cleavage site. A “tumor-associated proteasecleavage site” as provided herein is an amino acid sequence recognizedby a protease whose expression is specific or upregulated for a tumorcell or tumor cell environment thereof. In some embodiments, theprotease cleavage site is a cleavage site recognized by one or moreenzyme selected from the group consisting of: ABHD12, ADAM12, ABHD12B,ABHD13, ABHD17A, ADAM19, ADAM20, ADAM21, ADAM28, ADAM30, ADAM33, ADAMS,ABHD17A, ADAMDEC1, ADAMTS1, ADAMTS10, ADAMTS12, ADAMTS13, ADAMTS14,ADAMTS15, ADAMTS16, ADAMTS17, ADAMTS18, ADAMTS19, ADAMTS2, ADAMTS20,ADAMTS3, ADAMTS4, ABHD17B, ADAMTS5, ADAMTS6, ADAMTS7, ADAMTS8, ADAMTS9,ADAMTSL1, ADAMTSL2, ADAMTSL3, ABHD17C, ADAMTSL5, ASTL, BMP1, CELA1,CELA2A, CELA2B, CELA3A, CELA3B, ADAM10, ADAM15, ADAM17, ADAMS, ADAMTS4,CTSE, CTSF, ADAMTSL4, CMA1, CTRB1, CTRC, CTSO, CTR1, CTSA, CTSW, CTSB,CTSC, CTSD, ESP1, CTSG, CTSH, GZMA, GZMB, GZMH, CTSK, GZMM, CTSL, CTSS,CTSV, CTSZ, HTRA4, KLK10, KLK11, KLK13, KLK14, KLK2, KLK4, DPP4, KLK6,KLK7, KLKB1, ECE1, ECE2, ECEL1, MASP2, MEP1A, MEP1B, ELANE, FAP, GZMA,MMP11, GZMK, HGFAC, HPN, HTRA1, MMP11, MMP16, MMP17, MMP19, HTRA2,MMP20, MMP21, HTRA3, HTRA4, KEL, MMP23B, MMP24, MMP25, MMP26, MMP27,MMP28, KLK5, MMP3, MMP7, MMP8, MMP9, LGMN, LNPEP, MASP1, PAPPA, PAPPA2,PCSK1, NAPSA, PCSK5, PCSK6, MME, MMP1, MMP10, PLAT, PLAU, PLG, PRSS1,PRSS12, PRSS2, PRSS21, PRSS3, PRSS33, PRSS4, PRSS55, PRSS57, MMP12,PRSS8, PRSS9, PRTN3, MMP13, MMP14, ST14, TMPRSS10, TMPRSS11A, TMPRSS11D,TMPRSS11E, TMPRSS11F, TMPRSS12, TMPRSS13, MMP15, TMPRSS15, MMP2,TMPRSS2, TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS6, TMPRSS7, TMPRSS9, NRDC,OVCH1, PAMR1, PCSK3, PHEX, TINAG, TPSAB1, TPSD1, and TPSG1. In someembodiments, the protease cleavage site is a cleavage site recognized byone or more enzyme selected from the group consisting of: ADAM17, HTRA1,PRSS1, FAP, GZMK, NAPSA, MMP1, MMP2, MMP9, MMP10, MMP7, MMP12, MMP28,ADAMTS9, HGFAC, and HTRA3.

In embodiments, the protease cleavage site is a matrix metalloprotease(MMP) cleavage site, a disintegrin and metalloprotease domain-containing(ADAM) metalloprotease cleavage site, a prostate specific antigen (PSA)protease cleavage site, a urokinase-type plasminogen activator (uPA)protease cleavage site, a membrane type serine protease 1 (MT-SP1)protease cleavage site, a matriptase protease cleavage site (ST14) or alegumain protease cleavage site. In embodiments, the matrixmetalloprotease (MMP) cleavage site is a MMP9 cleavage site, a MMP13cleavage site or a MMP2 cleavage site. In embodiments, the disintegrinand metalloprotease domain-containing (ADAM) metalloprotease cleavagesite is an ADAM9 metalloprotease cleavage site, a ADAM10 metalloproteasecleavage site or a ADAM17 metalloprotease cleavage site. Proteasecleavage sites may be designated by a specific amino acid sequence.

In some embodiments, the cleavable peptide is cleaved by one or moreenzyme selected from the group consisting of: ABHD12, ADAM12, ABHD12B,ABHD13, ABHD17A, ADAM19, ADAM20, ADAM21, ADAM28, ADAM30, ADAM33, ADAMS,ABHD17A, ADAMDEC1, ADAMTS1, ADAMTS10, ADAMTS12, ADAMTS13, ADAMTS14,ADAMTS15, ADAMTS16, ADAMTS17, ADAMTS18, ADAMTS19, ADAMTS2, ADAMTS20,ADAMTS3, ADAMTS4, ABHD17B, ADAMTS5, ADAMTS6, ADAMTS7, ADAMTS8, ADAMTS9,ADAMTSL1, ADAMTSL2, ADAMTSL3, ABHD17C, ADAMTSL5, ASTL, BMP1, CELA1,CELA2A, CELA2B, CELA3A, CELA3B, ADAM10, ADAM15, ADAM17, ADAM9, ADAMTS4,CTSE, CTSF, ADAMTSL4, CMA1, CTRB1, CTRC, CTSO, CTR1, CTSA, CTSW, CTSB,CTSC, CTSD, ESP1, CTSG, CTSH, GZMA, GZMB, GZMH, CTSK, GZMM, CTSL, CTSS,CTSV, CTSZ, HTRA4, KLK10, KLK11, KLK13, KLK14, KLK2, KLK4, DPP4, KLK6,KLK7, KLKB1, ECE1, ECE2, ECEL1, MASP2, MEP1A, MEP1B, ELANE, FAP, GZMA,MMP11, GZMK, HGFAC, HPN, HTRA1, MMP11, MMP16, MMP17, MMP19, HTRA2,MMP20, MMP21, HTRA3, HTRA4, KEL, MMP23B, MMP24, MMP25, MMP26, MMP27,MMP28, KLK5, MMP3, MMP7, MMP8, MMP9, LGMN, LNPEP, MASP1, PAPPA, PAPPA2,PCSK1, NAPSA, PCSK5, PCSK6, MME, MMP1, MMP10, PLAT, PLAU, PLG, PRSS1,PRSS12, PRSS2, PRSS21, PRSS3, PRSS33, PRSS4, PRSS55, PRSS57, MMP12,PRSS8, PRSS9, PRTN3, MMP13, MMP14, ST14, TMPRSS10, TMPRSS11A, TMPRSS11D,TMPRSS11E, TMPRSS11F, TMPRSS12, TMPRSS13, MMP15, TMPRSS15, MMP2,TMPRSS2, TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS6, TMPRSS7, TMPRSS9, NRDC,OVCH1, PAMR1, PCSK3, PHEX, TINAG, TPSAB1, TPSD1, and TPSG1. In someembodiments, the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of: ADAM17, HTRA1, PRSS1, FAP, GZMK,NAPSA, MMP1, MMP2, MMP9, MMP10, MMP7, MMP12, MMP28, ADAMTS9, HGFAC, andHTRA3. In some embodiments, the cleavable peptide is cleaved by one ormore enzyme selected from the group consisting of uPA and MMP14. In someembodiments, the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of matriptase and MMP14. In someembodiments, the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of legumain and MMP14. In someembodiments, the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of matriptase and uPA. In someembodiments, the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of uPA and legumain. In someembodiments, the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of matriptase and legumain. In someembodiments, the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of uPA, matriptase, and MMP14. Insome embodiments, the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of uPA, legumain, and MMP14. In someembodiments. the cleavable peptide is cleaved by one or more enzymeselected from the group consisting of matriptase, legumain, and MMP14.In some embodiments, the cleavable peptide is cleaved by one or moreenzyme selected from the group consisting of matriptase. legumain, anduPA.

In some embodiments, the cleavable peptide is a substrate for a proteasethat is co-localized in a region or a tissue expressing a cytokinereceptor. The cytokine receptor can be any cytokine receptor. In someembodiments, the cytokine receptor is selected from the group consistingof CXCR1, CXCR2. CXCR3, CXCR4, CXCR5. CXCR6, CXCR7, CCR1, CCR2, CCR3,CCR4, CCR5, CCR6, CCR7, CCR8, CCR9, CCR10, CCR11, XCR1, CX3CR1, IL-1RAP,IL-1RAPL1, IL-1RAPL2, IL-1RL1, IL-1RL2, IL-1R1, IL-1R2, IL-2R, IL-2Rα,IL-2Rβ, IL-2Rγ, IL-3Rα, IL-4R, IL-5Rα, IL-6R, IL-6ST, IL-7R, IL-9R,IL-10Rα, IL-10Rβ, IL-1 Rα, IL-12Rβ1, IL-12Rβ2. IL-13Rα1, IL-13Rα2,IL-15Rα, IL-17RA, IL-17RB, IL-17RC, IL-17RD, IL-17RE, IL-18RAP, IL-18R1,IL-20Rα, IL-20Rβ, IL-2IR, IL-22Rα1, IL-22Rα2, IL-23R, IL-27Rα, IL-28Rα,IL-31RA, IFNAR1, IFNAR2, IFNGR1, IFNGR2, IFNLR1, GMRα (CD116), CD131,GHR, PRLR, EPOR, LIFR (CD118), OSMRP, TPO-R (CDI 10), CSF-1R, EDAR,TNFRSF1A, TNFRSF1B, LTBR, TNFRSF4, CD40, FAS, TNFRSF6B, CD27, TNFRSF8,TNFRSF9. TNFRSF10A, TNFRSF10B, TNFRSF10C, TNFRSF10D, TNFRSF11A,TNFRSF11B, TNFRSF12A. TNFRSF13B, TNFRSF13C, TNFRSF14, NGFR, TNFRSF17,TNFRSF18, TNFRSF19, RELT, TNFRSF21, TNFRSF25, and EDA2R.

In some embodiments, the cleavable peptide is a 5-mer (i.e. peptide 5amino acids in length), 6-mer (i.e. peptide 6 amino acids in length).7-mer (i.e. peptide 7 amino acids in length), 8-mer (i.e. peptide 8amino acids in length), 9-mer (i.e. peptide 9 amino acids in length),10-mer (i.e. peptide 10 amino acids in length), 11-mer (i.e. peptide 11amino acids in length), 12-mer (i.e. peptide 12 amino acids in length),13-mer (i.e. peptide 13 amino acids in length), 14-mer (i.e. peptide 14amino acids in length), 15-mer (i.e. peptide 15 amino acids in length),16-mer (i.e. peptide 16 amino acids in length). 17-mer (i.e. peptide 17amino acids in length), or 18-mer (i.e. peptide 18 amino acids inlength). Exemplary cleavable peptide sequences are shown in Table 1.

TABLE 1 Exemplary cleavable peptide sequences MPYDLYHP (SEQ ID NO: 961GGIGQLTSVLMAAP (SEQ ID NO: 129) GGIGQLTA (SEQ ID NO: 97)DSGGFMLTLVLPVLP (SEQ ID NO: 130) DLGRFQTF (SEQ ID NO: 98)TSEFVFAPDLGRFQTF (SEQ ID NO: 131) DSGGFMLT (SEQ ID NO: 99)TSTSGRSANPR (SEQ ID NO: 132) TSVLMAAP (SEQ ID NO: 100)TSTSGRSANPG (SEQ ID NO: 133) TSEFVFAPDQ (SEQ ID NO: 101)TSTSGRSANPH (SEQ ID NO: 134) KLVLPV (SEQ ID NO: 102)VPLSLY (SEQ ID NO: 135) KPILFFRL (SEQ ID NO: 17)TSASGASASAA (SEQ ID NO: 136) ANQLKG (SEQ ID NO: 104)PSSPGGSSP (SEQ ID NO: 137) QSQLKE (SEQ ID NO: 105)ISSGLLSGRSDNH (SEQ ID NO: 138) HEQLTV (SEQ ID NO: 106)ISSGLLSGRSDDH (SEQ ID NO: 139) PANLVAPDP (SEQ ID NO: 107)ISSGLLSGRSDIH (SEQ ID NO: 140) PAPGVYPGP (SEQ ID NO: 108)ISSGLLSGRSDQH (SEQ ID NO: 41) APAGLIVPYN (SEQ ID NO: 109)ISSGLLSGRSDTH (SEQ ID NO: 142) PQALVA (SEQ ID NO: 110)ISSGLLSGRSANP (SEQ ID NO: 143) VGNLNF (SEQ ID NO: 111)ISSGLLSGRSDNP (SEQ ID NO: 144) VANLLYE (SEQ ID NO:112)ISSGLLSGRSANPRG (SEQ ID NO: 145) VYNLMD (SEQ ID NO: 113)AVGLLAPPGGLSGRSDNH (SEQ ID NO: 146) TFNIKQ (SEQ ID NO: 114)AVGLLAPPGGLSGRSDDH (SEQ ID NO: 147) DLWKLLP (SEQ ID NO: 115)AVGLLAPPGGLSGRSDIH (SEQ ID NO: 148) PGSTKRA (SEQ ID NO: 116)AVGLLAPPGGLSGRSDQH (SEQ ID NO: 149) QQYRALKS (SEQ ID NO: 17)AVGLLAPPGGLSGRSDTH (SEQ ID NO: 150) YVPRAVL (SEQ ID NO: 118)AVGLLAPPGGLSGRSANP (SEQ ID NO: 151) GVNKWPT (SEQ ID NO: 119)AVGLLAPPGGLSGRSDNP (SEQ ID NO: 152) LAQAVRSS (SEQ ID NO: 120)AVGLLAPPSGRSANPRG (SEQ ID NO: 15$) RAAAVKSP (SEQ ID NO: 121)SGRSA (SEQ ID NO: 236) DLLAVVAAS (SEQ ID NO: 122)SGRSANA (SEQ ID NO: 237) VQTVTWPD (SEQ ID NO: 123SGRNAQ (SEQ ID NO: 238) AIPMSIPP (SEQ ID NO: 124)SGRNAQVR (SEQ ID NO: 239) GYEVHHQK (SEQ ID NO:125)SGRSDN (SEQ ID NO: 240) VHHQKLVF (SEQ ID NO: 126)SGRSDNPN (SEQ ID NO: 241) IRRVSYSF (SEQ ID NO: 127)GSGKSA (SEQ ID NO: 242) MPYDLYHPILFFRL (SEQ ID NO: 128)DSGGFMLTS (SEQ ID NO: 264) ISSGLLGGLSGRSDQP (SEQ ID NO: 270)IYDQKT (SEQ ID NO: 342) ISSGLLSGRSDQG (SEQ ID NO: 271)AHNYKT (SEQ ID NO: 343) ISSGLLSGRSDQA (SEQ ID NO272)NNDQAN (SEQ ID NO: 344) ISSGLLSGRSDSP (SEQ ID NO: 273)MLGEFVSE (SEQ ID NO: 345) ISSGLLSGRSDTP (SEQ ID NO: 274)GLVALRGA (SEQ ID NO: 346) ISSGLLSGRSDMP (SEQ ID NO: 275)KEHKYKAE (SEQ ID NO: 347) ISSGLLSGRSD (SEQ ID NO: 276)RQARVVG (SEQ ID NO: 356) ISSGLLSGRSDQP (SEQ ID NO: 277)LGGSGRSNAQVRLE (SEQ ID NO: 357) ISSGLLGGLSGRSDNP (SEQ ID NO: 278)LGGSGRKASLSLE (SEQ ID NO: 358) ISSGLLSSGGLSGRSDQP (SEQ ID NO: 279)SGRIGFLRTA (SEQ ID NO: 359) ISSGLLSSGGLSGRSDNP (SEQ ID NO: 280)SGAIGFLRTA (SEQ ID NO: 360) ISSGLLSGRS (SEQ ID NO: 281)RPARSGRSAGGSVA (SEQ ID NO: 361) ISSGLLSGRSESP (SEQ ID NO: 282)VTGRGDSPASS (SEQ ID NO: 362) ISSGLLSGRSEQP (SEQ ID NO: 283)PRFKIIGG (SEQ ID NO: 363) ISSGLLSGRSEQH (SEQ ID NO: 284)LSGRIGFLRTA (SEQ ID NO: 364) LSSGLLSORSDQP (SEQ ID NO: 285)LSGRSNAMPYDLYHP (SEQ ID NO: 365) LSSGLLGGLSGRSDQP (SEQ ID NO: 286)LSGRSNAGGIGQLTA (SEQ ID NO: 366) LSSGLLSGRSDQG (SEQ ID NO: 287)LSGRSNAVPLSLY (SEQ ID NO: 367) LSSGLLSGRSDQA (SEQ ID NO: 288)LSGRSNADSGGFMLT (SEQ ID NO: 368) LSSGLLSGRSDSP (SEQ ID NO: 289)LSGRSNAHEQLTA (SEQ ID NO: 369) LSSGLLSGRSDTP (SEQ ID NO: 290)LSGRSNARAAAVKSP (SEQ ID NO: 370) LSSGLLSGRSDMP (SEQ ID NO: 291)LSGRSNATSVLMAAP (SEQ ID NO: 371) LSSGLLSGRSD (SEQ ID NO: 292)VPLSLYLSGRSNA (SEQ ID NO: 372) GKQLRVVNEYSSMDNMLLG (SEQ ID NO: 293)DSGGFMLTLSGRSNA (SEQ ID NO: 373) LSSGLLGGLSGRSDNP (SEQ ID NO: 294)GGIGQLTALSGRSNA (SEQ ID NO: 374) LSSGLLSSGGLSGRSDQP (SEQ ID NO: 295)MPYDLYHPLSGRSNA (SEQ ID NO: 375) LSSGLLSSGGLSGRSDNP (SEQ ID NO: 296)HEQLTVLSGRSNA (SEQ ID NO: 376) GKQLRVVNEYSSEDNMLLG (SEQ ID NO: 297)RAAAVKSPLSGRSNA (SEQ ID NO: 377) LSSGLLSGRSESP (SEQ ID NO: 298)TSVLMAAPLSGRSNA (SEQ ID NO: 378) LSSGLLSGRSEQP (SEQ ID NO: 299)IPVSLRSGRSNAQRLE (SEQ ID NO: 379) LSSGLLSGRSEQH (SEQ ID NO: 300)VPLSLYRQARVVG (SEQ ID NO: 380) MPYDLYH (SEQ ID NO: 301)DSGGFMLTRQARVVG (SEQ ID NO: 381) LSGRSDNH (SEQ ID NO: 302)GGIGQLTARQARVVG (SEQ ID NO: 382) GSIPVSLRSG (SEQ ID NO: 306)MPYDLYHPRQARVVG (SEQ ID NO: 383) GPSGPAGLKGAPG (SEQ ID NO: 307)HEQLTVRQARVVG (SEQ ID NO: 384) GPPGPAGMKGLPG (SEQ ID NO: 308)RAAAVKSPRQARVVG (SEQ ID NO: 385) GYVADAPK (SEQ ID NO: 309)TSVLMAAPRQARVVG (SEQ ID NO: 386) KKLADEPE (SEQ ID NO: 310)KQLRVVNEYSSMDNMLLG (SEQ ID NO: 387) GGSRPAHLRDSGK (SEQ ID NO: 311)KQLRVVNEYSSEDNMLLG (SEQ ID NO: 388) SFTQARVVGG (SEQ ID NO: 312)KQLRVVNGYSSEDNMLLG (SEQ ID NO: 389) VHMPLGFLGPRQARVVN (SEQ ID NO: 313)KQLRVVGGLVHLKNTMET (SEQ ID NO: 390) LSGRSDNHSPLGLAGS (SEQ ID NO: 314)TRDRLDEVNFKQLRVVNG (SEQ ID NO: 391) VPLSLYSG (SEQ ID NO: 315)TRDRLDEVNFKLLRVVNG (SEQ ID NO: 392) IPESLRAG (SEQ ID NO: 316)TRDRLDPVNFKQLRVVNG (SEQ ID NO: 393) IPVSLRSG (SEQ ID NO: 317)TRDRLDPVNFKLLRVVNG (SEQ ID NO: 394) TYSRSKYLATA (SEQ ID NO: 399)NPMGSEPVNFKQLRVVNG (SEQ ID NO: 395) TYSTSRYLATA (SEQ ID NO: 400)NPMGSEPVNFKQLRVVNG (SEQ ID NO: 396) KQLRVVNEYSSE (SEQ ID NO: 401)NPMGSDPVNFKQLRVVNG (SEQ ID NO: 397) KQLRVVNGYSSE (SEQ ID NO: 402)NPMGSDPVNFKLLRVVNG (SEQ ID NO: 398) KQLRVVGGLVAL (SEQ ID NO: 403)AGQPKQLRVVNG (SEQ ID NO: 494) KQLRVVNGLVAL (SEQ ID NO: 404)AGQPLQLRVVNG (SEQ ID NO: 495) SPGRVVGGLVAL (SEQ ID NO: 405)AGQPLQERVVNG (SEQ ID NO: 496) PQPRTYSRSRYL (SEQ ID NO: 406)AGQPKQERVVNG (SEQ ID NO: 497) PQPRTTSRSRYL (SEQ ID NO: 407)GTANKQLRVVNG (SEQ ID NO: 498) VVNEYSSSRGPYH (SEQ ID NO: 408)GTANQLHVVNG (SEQ ID NO: 499) VVNEYSSERGPYH (SEQ ID NO: 409)GTANIQLRVVNG (SEQ ID NO: 500) NKVSMSSSRGPYH (SEQ ID NO: 410)GTANIQLHVVNG (SEQ ID NO: 501) NKVSMSSTRGPYH (SEQ ID NO: 411)KQLRTVAGLAGK (SEQ ID NO: 504) APAMMRGSVILTV (SEQ ID NO: 412)KQLRTVNGLAGK (SEQ ID NO: 505) APAMMEGSVILTV (SEQ ID NO: 413)KQLRVVAGLAGK (SEQ ID NO: 506) RGSVIITVQTVTW (SEQ ID NO: 414)KQLRVVNGLAGK (SEQ ID NO: 507) RGSVILTVQTVTW (SEQ ID NO: 415)GIKYKQLRVVNG (SEQ ID NO: 508) RKGKALAAYRLE (SEQ ID NO: 420)GIKYKYLRVVNG (SEQ ID NO: 509) RKGKAGAAYRLE (SEQ ID NO: 421)GIKYLQLRVVNG (SEQ ID NO: 510) RQARVVGGLVAL (SEQ ID NO: 422)GIKYLYLRVVNG (SEQ ID NO: 511) GGVRGPRFKIIGG (SEQ ID NO: 423)THLDLTYSRSKYLATA (SEQ ID NO: 512) GGVRGPRVKIIGG (SEQ ID NO: 424)THLDLTPSRSKYLATA (SEQ ID NO: 513) VTGRGDSHSLTTN (SEQ ID NO: 425)THLDLTSRSRYLATA (SEQ ID NO: 514) VTGRGDSPSLTTN (SEQ ID NO: 426)THLDLTPSRSRYLATA (SEQ ID NO: 515) TGHGQASQGLLDR (SEQ ID NO: 427)TYSRSKYLAPANGNAE (SEQ ID NO: 516) TGHGQASSGLLDR (SEQ ID NO: 428)TYSRSKYLATANGNAE (SEQ ID NO: 517) KQLRYVNENLENY (SEQ ID NO: 429)TYSRSRYLAPANGNAE (SEQ ID NO: 5183 KQLRVVNGNLENY (SEQ ID NO: 430)TYSRSRYLATANGNAE (SEQ ID NO: 519) SNVNDVANYNFF (SEQ ID NO: 431)DPVNFKQLRVVNEYSSE (SEQ ID NO: 520) SNVNDVSNYNFF (SEQ ID NO: 432)DPVNFKQLRVVNGYSSE (SEQ ID NO: 521) IDFNAAQNLYEK (SEQ ID NO: 433)DPVNFKKLRVVNEYSSE (SEQ ID NO: 522) IDFNAAYNLYEK (SEQ ID NO: 434)DPVNFKKLRVVNGYSSE (SEQ ID NO: 523) IQWNAGQPLQER (SEQ ID NO: 435)RKGKAGAAKNLNEKDY (SEQ ID NO: 524) IQWNAPQLQER (SEQ ID NO: 436)RKGKAGAAKNLYEKDY (SEQ ID NO: 525) SMDNRLLGLFGE (SEQ ID NO: 437)RKGKAGAAQNLNEKDY (SEQ ID NO: 526) SMDNMLLGLFGE (SEQ ID NO: 438)RKGKAGAAQNLYEKDY (SEQ ID NO: 527) VPIDDPQDLLEG (SEQ ID NO: 439)VTGRGDSHSLTKNQVSL (SEQ ID NO: 528) VPIDDPEDLLEG (SEQ ID NO: 440)VTGRGDSHSLTTNQVSL (SEQ ID NO: 529) IPENLPPGLPLT (SEQ ID NO: 441)VTGRGDSPSLTKNQVSL (SEQ ID NO: 530) IPENLPPLLPLT (SEQ ID NO: 442)VTGRGDSPSLTTNQVSL (SEQ ID NO: 531) QPPSLTKNQVSL (SEQ ID NO: 443)TGHQASSERSSNIRTS (SEQ ID NO: 532) QPPSLTRNQVSL (SEQ ID NO: 444)TGHGQASSERSSNSRTS (SEQ ID NO: 533) DSHSLTKNQVSL (SEQ ID NO: 445)TGHGQASSERSSTIRTS (SEQ ID NO: 534) DSHSLTTNQVSL (SEQ ID NO: 446)TGHGQASSERSSTSRTS (SEQ ID NO: 535) KAIQLTKNQVSL (SEQ ID NO: 447)DPVNFKLLRVVNEYSSE (SEQ ID NO: 538) KAIQLTYNQVSL (SEQ ID NO: 448)DPVNFKLLRVVNGYSSE (SEQ ID NO: 539) AEPWTNRNTDGS (SEQ ID NO: 449)DPVNFKQLRVVGGLVAL (SEQ ID NO: 540) AEPWTVRNTDGS (SEQ ID NO: 450)DPVNFKQLRVVNGLVAL (SEQ ID NO: 541) KQLRVVNG (SEQ ID NO: 451)DPVNFKLLRVVNGLVAL (SEQ ID NO: 542) KQLRVVTGRGDSP (SEQ ID NO: 452)DPVNFKLLRVVNGLVAL (SEQ ID NO: 543) KQLRVVNGRGDSP (SEQ ID NO: 453)KQLRVQNGDSTE (SEQ ID NO: 544) PSSRRRVVRKGVS (SEQ ID NO: 454)KQLRVVNNDATE (SEQ ID NO: 545) PSSRRRVNRKGVS (SEQ ID NO: 455)KQLRVVNGDSTE (SEQ ID NO: 546) SPGRVVTGRGDSP (SEQ ID NO: 46)ISNNKQLRVVNG (SEQ ID NO: 547) SPGRVVGGRGDSP (SEQ ID NO: 457)ISNNKQLPVVNG (SEQ ID NO: 548) NSGRAVTGRGDSP (SEQ ID NO: 458)ISNNEQLRVVNG (SEQ ID NO: 549) NSGRAVTYRGDSP (SEQ ID NO: 459)ISNNEQLPVVNG (SEQ ID NO: 550) TGHGQPSSRRRVN (SEQ ID NO: 460)KVSNKQLRVVNG (SEQ ID NO: 551) TGHGQASSRRRVN (SEQ ID NO: 461)KVSNKQLPVVNG (SEQ ID NO: 552) TGHGQSSSRGPYH (SEQ ID NO: 462)KVSNKALRVVNG (SEQ ID NO: 553) TGHGQASSRGPYH (SEQ ID NO: 463)KVSNKALPVVNG (SEQ ID NO: 554) RGSVILTKNQVSL (SEQ ID NO: 464)KQLRVQNNDATE (SEQ ID NO: 555) RGSVILTVNQVSL (SEQ ID NO: 465)TGHGQRSSNIRTS (SEQ ID NO: 480) SPGRVVGINYWLA (SEQ ID NO: 466)TGHGQASSNIRTS (SEQ ID NO. 481) SPGRVVGGNYWLA (SEQ ID NO: 467)TGHGQHSSNIANI (SEQ ID NO: 482) SPGRVVGSNKGAI (SEQ ID NO: 468)TGHGQASSNIANI (SEQ ID NO: 483) SPGRVVGGNKGAI (SEQ ID NO: 469)TGHGQASRNDYSY (SEQ ID NO: 484) PGARGRAPNHAVV (SEQ ID NO: 470)TGHGQASSNDYSY (SEQ ID NO: 485) PGARGRAFNHAVV (SEQ ID NO: 471)KALHVTNRNTDGS (SEQ ID NO: 486) PGARGNAFNNLDR (SEQ ID NO: 472)KALHVTNINTDGS (SEQ ID NO: 487) PGARGRAFNNLDR (SEQ ID NO: 473)RVVRKKVSNKALP (SEQ ID NO: 488) VSNKYISNNEQLP (SEQ ID NO: 474)RVVRKGVSNKALP (SEQ ID NO: 489) VSNKYFSNNEQLP (SEQ ID NO: 475)RQARVVGINYWLA (SEQ ID NO: 490) KVSNKALHVTNI (SEQ ID NO: 476)RQARVVGGNYWLA (SEQ ID NO: 491) KVSNKALPVTNI (SEQ ID NO: 477)VTGRGPSPDVPLT (SEQ ID NO: 478) VTGRGDSPDVPLT (SEQ ID NO: 479)

In some embodiments, the cleavable peptide comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153,236-242, 264, 270-302, 306-317, 342-347, 356-415, 420-491, 494-501,504-535, and 538-555. In some embodiments, the cleavable peptidecomprises an amino acid sequence selected from the group consisting ofSEQ IIS NOs: 270-302, 306-317, 342-347, 356-415, 420-491, 494-501,504-535, and 538-555. In some embodiments, the cleavable peptidecomprises an amino acid sequence selected from the group consisting ofSEQ ILS NOs: 281, 293, 297, 399-415, 420-491, 494-501, 504-535, and538-555. In some embodiments, the clearable peptide comprises the aminoacid sequence of SEQ ID NO: 96. In some embodiments, the clearablepeptide comprises the amino acid sequence o SEQ ID NO: 264. In someembodiments, the cleavable peptide comprises an amino acid. sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 156-415, 420-491, 494-501, 504-535, and 538-555, andan amino acid sequence selected from the group consisting of SEQ ID NOs:236-242. In some embodiments, :the clearable peptide comprises an aminoacid sequence selected from the group consisting of SEQ ID NOs: 96-131,and 264, and an amino acid sequence selected from the group consistingof SEQ ID NOs: 236-242. In some embodiments, the cleavable peptidecomprises an amino acid sequence selected from the group consisting, ofSEQ. ID NOs: 96-131, and an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 236-242. in embodiments in which the clearablepeptide comprises an amino acid sequence selected from the groupconsisting of SEQ NOs: 96-153, 264, 270-302., 306-317, 342-347, 356-415,420-491, 494-501, 504-535, and 538-555, and an amino acid sequenceselected from the group consisting of SEQ ID NOs: 236-242, the two aminoacid sequences may be linked in any order. For example, in embodimentsin which the cleavable peptide comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, andan amino acid sequence selected from the group consisting of SEQ ID NOs:236-242, the amino acid sequence selected from the group consisting ofSEQ ID NOs: 96-153, 236-242, 264, 270-302, 306-317, 342-347, 356-415,420-491, 494-501, 504-535, and 538-555 comprises an N-terminus and aC-terminus, and the amino acid sequence selected from the groupconsisting of SEQ ID NOs: 236-242 is linked to the N-terminus or theC-terminus of the amino acid sequence selected from the group consistingof SEQ ID NOs: 96-153, 264, 270-302, 306-317, 342-347, 356-415, 420-491,494-501, 504-535, and 538-555. In some embodiments in which thecleavable peptide comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 96-131, and 264, and an amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242, theamino acid sequence selected from the group consisting of SEQ ID NOs:96-131, and 264, comprises an N-terminus and a C-terminus, and the aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242is linked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-131, and 264.

In some embodiments, one or more additional amino acids are incorporatedby addition into to the amino acid sequence of the cleavable peptide. Insome embodiments, the one or more amino acids that are incorporated byaddition into the amino acid sequence of the cleavable peptide areselected from the group consisting of hydrophilic amino acids (e.g.,lysine, arginine, histidine, aspartic acid, glutamic acid, serine,threonine, asparagine, or glutamine), hydrophobic amino acids (e.g.,alanine, valine, isoleucine, leucine, methionine, phenylalanine,tyrosine, tryptophan, cysteine, glycine, or proline), polar amino acids(e.g., serine, threonine, cysteine, asparagine, glutamine, or tyrosine),nonpolar amino acids (e.g., glycine, alanine, valine, proline, leucine,isoleucine, methionine, tryptophan, or phenylalanine), amino acids withaliphatic side chains (e.g., glycine, alanine, valine, leucine, orisoleucine), amino acids with hydroxyl-containing side chains (e.g.,serine or threonine), amino acids with sulfur-containing side chains(e.g., cysteine or methionine), charged amino acids (e.g., arginine,lysine, aspartic acid, or glutamic acid), uncharged amino acids (e.g.,serine, threonine, asparagine, or glutamine), aromatic amino acids(e.g., tyrosine, tryptophan, or phenylalanine), cyclic amino acids(e.g., proline), acidic amino acids (e.g., aspartic acid, asparagine,glutamic acid, or glutamine), basic amino acids (e.g., histidine,lysine, or arginine), and bulky amino acids (e.g., phenylalanine,tyrosine, or tryptophan). In some embodiments, a glycine (G) isincorporated by addition to the N-terminus and/or C-terminus of theamino acid sequence of the cleavable peptide. In some embodiments, aglycine (G) and a proline (P) are incorporated by addition to theN-terminus and/or C-terminus of the amino acid sequence of the cleavablepeptide, such as by incorporating the amino acid sequence GP or PG tothe N-terminus and/or C-terminus of the amino acid sequence of thecleavable peptide.

The cleavable peptide comprises an amino-terminus and acarboxy-terminus. In some embodiments, the cleavable peptide is linkedto an N-terminal spacer domain and/or a C-terminal spacer domain. Insome embodiments, an N-terminal spacer domain is linked to theamino-terminus of the cleavable peptide. In some embodiments, aC-terminal spacer domain is linked to the carboxy-terminus of thecleavable peptide. In some embodiments, an N-terminal spacer domain islinked to the amino-terminus of the cleavable peptide, and a C-terminalspacer domain is linked to the carboxy-terminus of the cleavablepeptide. In some embodiments, an N-terminal spacer domain is linked tothe amino-terminus of the cleavable peptide, and a C-terminal spacerdomain is linked to the carboxy-terminus of the cleavable peptide.

In some embodiments, the amino-terminus of the cleavable peptide islinked to a component other than the N-terminal spacer domain. In someembodiments, the carboxy-terminus of the cleavable peptide is linked toa component other than the C-terminal spacer domain. In someembodiments, a masking moiety is linked to the amino-terminus or thecarboxy-terminus of the cleavable peptide. In some embodiments, acytokine or functional fragment thereof is linked to the amino-terminusor the carboxy-terminus of the cleavable peptide. In some embodiments, ahalf-life extension domain is linked to the amino-terminus or thecarboxy-terminus of the cleavable peptide. In some embodiments, a firsthalf-life extension domain is linked to the amino-terminus or thecarboxy-terminus of the cleavable peptide. In some embodiments, a secondhalf-life extension domain is linked to the amino-terminus or thecarboxy-terminus of the cleavable peptide.

2. Spacer Domains

In some embodiments, the linker comprises a spacer domain. As usedherein, a “spacer domain” may, in some embodiments, refer to anN-terminal spacer domain and/or a C-terminal spacer domain. In someembodiments, the linker comprises an N-terminal spacer domain and/or aC-terminal spacer domain. In some embodiments, the linker comprises anN-terminal spacer domain. In some embodiments, the linker comprises aC-terminal spacer domain. In some embodiments, the linker comprises anN-terminal spacer domain and a C-terminal spacer domain. In someembodiments, the linker comprises an N-terminal spacer domain and acleavable peptide. In some embodiments, the linker comprises a cleavablepeptide and a C-terminal spacer domain. In some embodiments, the linkercomprises an N-terminal spacer domain, a cleavable peptide, and aC-terminal spacer domain.

In some embodiments, such as some embodiments having more than oneN-terminal spacer domain, an N-terminal spacer domain may be referred toas a first N-terminal spacer domain, a second N-terminal spacer domain,or a third N-terminal spacer domain, each of which is considered “anN-terminal spacer domain” and may be any of the N-terminal spacerdomains described herein. Likewise, in some embodiments, such as someembodiments having more than one C-terminal spacer domain, a C-terminalspacer domain may be referred to as a first C-terminal spacer domain, asecond C-terminal spacer domain, or a third C-terminal spacer domain,each of which is considered “a C-terminal spacer domain” and may be anyof the C-terminal spacer domains described herein. For example,reference to “an N-terminal spacer domain” or “the N-terminal spacerdomain” can refer to the N-terminal spacer domain in a masked cytokinecomprising a single N-terminal spacer domain, or it can refer to thefirst N-terminal spacer domain in a masked cytokine comprising a firstN-terminal spacer domain and a second N-terminal spacer domain, or itcan refer to the second N-terminal spacer domain in a masked cytokinecomprising a first N-terminal spacer domain and a second N-terminalspacer domain, or it can refer to the first N-terminal spacer domain andthe second N-terminal spacer domain in a masked cytokine comprising afirst N-terminal spacer domain and a second N-terminal spacer domain, orit can refer to the first N-terminal spacer domain, the secondN-terminal spacer domain, and/or the third N-terminal spacer domain in amasked cytokine comprising a first N-terminal spacer domain, a secondN-terminal spacer domain, and a third N-terminal spacer domain.

The N-terminal spacer domain and the C-terminal spacer domain eachcomprise an amino-terminus and a carboxy-terminus. In some embodiments,a masking moiety is linked to the amino-terminus or the carboxy-terminusof the N-terminal spacer domain. In some embodiments, a cytokine orfunctional fragment thereof is linked to the amino-terminus or thecarboxy-terminus of the N-terminal spacer domain. In some embodiments, ahalf-life extension domain is linked to the amino-terminus or thecarboxy-terminus of the N-terminal spacer domain. In some embodiments, afirst half-life extension domain is linked to the amino-terminus or thecarboxy-terminus of the N-terminal spacer domain. In some embodiments, asecond half-life extension domain is linked to the amino-terminus or thecarboxy-terminus of the N-terminal spacer domain.

In some embodiments, a masking moiety is linked to the amino-terminus orthe carboxy-terminus of the C-terminal spacer domain. In someembodiments, a cytokine or functional fragment thereof is linked to theamino-terminus or the carboxy-terminus of the C-terminal spacer domain.In some embodiments, a half-life extension domain is linked to theamino-terminus or the carboxy-terminus of the C-terminal spacer domain.In some embodiments, a first half-life extension domain is linked to theamino-terminus or the carboxy-terminus of the C-terminal spacer domain.In some embodiments, a second half-life extension domain is linked tothe amino-terminus or the carboxy-terminus of the C-terminal spacerdomain.

In some embodiments, a masking moiety is linked to the amino-terminus ofthe N-terminal spacer domain, and a half-life extension domain is linkedto the carboxy-terminus of the N-terminal spacer domain. In someembodiments, a cytokine or functional fragment thereof is linked to theamino-terminus of the N-terminal spacer domain, and a half-lifeextension domain is linked to the carboxy-terminus of the N-terminalspacer domain. In some embodiments, a masking moiety is linked to thecarboxy-terminus of the N-terminal spacer domain and, a half-lifeextension domain is linked to the amino-terminus of the N-terminalspacer domain. In some embodiments, a cytokine or functional fragmentthereof is linked to the carboxy-terminus of the N-terminal spacerdomain, and a half-life extension domain is linked to the amino-terminusof the N-terminal spacer domain.

In some embodiments, a masking moiety is linked to the amino-terminus ofthe C-terminal spacer domain, and a half-life extension domain is linkedto the carboxy-terminus of the C-terminal spacer domain. In someembodiments, a cytokine or functional fragment thereof is linked to theamino-terminus of the C-terminal spacer domain, and a half-lifeextension domain is linked to the carboxy-terminus of the C-terminalspacer domain. In some embodiments, a masking moiety is linked to thecarboxy-terminus of the C-terminal spacer domain and, a half-lifeextension domain is linked to the amino-terminus of the C-terminalspacer domain. In some embodiments, a cytokine or functional fragmentthereof is linked to the carboxy-terminus of the C-terminal spacerdomain, and a half-life extension domain is linked to the amino-terminusof the C-terminal spacer domain.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the first masking moiety or the second masking moiety islinked to the amino-terminus of the N-terminal spacer domain, and acytokine or functional fragment thereof is linked to thecarboxy-terminus of the N-terminal spacer domain. In some embodimentscomprising a first masking moiety and a second masking moiety, the firstmasking moiety or the second masking moiety is linked to thecarboxy-terminus of the N-terminal spacer domain, and a cytokine orfunctional fragment thereof is linked to the amino-terminus of theN-terminal spacer domain.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the first masking moiety or the second masking moiety islinked to the amino-terminus of the C-terminal spacer domain, and acytokine or functional fragment thereof is linked to thecarboxy-terminus of the C-terminal spacer domain. In some embodimentscomprising a first masking moiety and a second masking moiety, the firstmasking moiety or the second masking moiety is linked to thecarboxy-terminus of the C-terminal spacer domain, and a cytokine orfunctional fragment thereof is linked to the amino-terminus of theC-terminal spacer domain.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the first masking moiety is linked to the amino-terminusof the C-terminal spacer domain, and the second masking moiety is linkedto the carboxy-terminus of the C-terminal spacer domain. In someembodiments comprising a first masking moiety and a second maskingmoiety, the first masking moiety is linked to the carboxy-terminus ofthe C-terminal spacer domain, and the second masking moiety is linked tothe amino-terminus of the C-terminal spacer domain.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the half-life extension domain is linked to theamino-terminus of the N-terminal spacer domain, and either the firstmasking moiety or the second masking moiety is linked to thecarboxy-terminus of the N-terminal spacer domain. In some embodimentscomprising a first masking moiety and a second masking moiety, thehalf-life extension domain is linked to the carboxy-terminus of theN-terminal spacer domain, and either the first masking moiety or thesecond masking moiety is linked to the amino-terminus of the N-terminalspacer domain.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the first masking moiety is linked to the amino-terminusof the N-terminal spacer domain, and the second masking moiety is linkedto the carboxy-terminus of the N-terminal spacer domain. In someembodiments comprising a first masking moiety and a second maskingmoiety, the first masking moiety is linked to the carboxy-terminus ofthe N-terminal spacer domain, and the second masking moiety is linked tothe amino-terminus of the N-terminal spacer domain.

In some embodiments comprising a first masking moiety and a secondmasking moiety, the half-life extension domain is linked to theamino-terminus of the C-terminal spacer domain, and either the firstmasking moiety or the second masking moiety is linked to thecarboxy-terminus of the C-terminal spacer domain. In some embodimentscomprising a first masking moiety and a second masking moiety, thehalf-life extension domain is linked to the carboxy-terminus of theC-terminal spacer domain, and either the first masking moiety or thesecond masking moiety is linked to the amino-terminus of the C-terminalspacer domain.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, a masking moiety is linked to theamino-terminus of the N-terminal spacer domain, and either the firsthalf-life extension domain or the second half-life extension domain islinked to the carboxy-terminus of the N-terminal spacer domain. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, a masking moiety is linked to thecarboxy-terminus of the N-terminal spacer domain, and either the firsthalf-life extension domain or the second half-life extension domain islinked to the amino-terminus of the N-terminal spacer domain. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, a cytokine or functional fragment thereof islinked to the amino-terminus of the N-terminal spacer domain, and eitherthe first half-life extension domain or the second half-life extensiondomain is linked to the carboxy-terminus of the N-terminal spacerdomain. In some embodiments comprising a first half-life extensiondomain and a second half-life extension domain, a cytokine or functionalfragment thereof is linked to the carboxy-terminus of the N-terminalspacer domain, and either the first half-life extension domain or thesecond half-life extension domain is linked to the amino-terminus of theN-terminal spacer domain.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, a masking moiety is linked to theamino-terminus of the C-terminal spacer domain, and either the firsthalf-life extension domain or the second half-life extension domain islinked to the carboxy-terminus of the C-terminal spacer domain. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, a masking moiety is linked to thecarboxy-terminus of the C-terminal spacer domain, and either the firsthalf-life extension domain or the second half-life extension domain islinked to the amino-terminus of the C-terminal spacer domain. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, a cytokine or functional fragment thereof islinked to the amino-terminus of the C-terminal spacer domain, and eitherthe first half-life extension domain or the second half-life extensiondomain is linked to the carboxy-terminus of the C-terminal spacerdomain. In some embodiments comprising a first half-life extensiondomain and a second half-life extension domain, a cytokine or functionalfragment thereof is linked to the carboxy-terminus of the C-terminalspacer domain, and either the first half-life extension domain or thesecond half-life extension domain is linked to the amino-terminus of theC-terminal spacer domain.

In some embodiments comprising a first half-life extension domain, asecond half-life extension domain, a first masking moiety, and a secondmasking moiety, the first masking moiety is linked to the amino-terminusof the N-terminal spacer domain, and the first half-life extensiondomain is linked to the carboxy-terminus of the N-terminal spacerdomain. In some embodiments comprising a first half-life extensiondomain, a second half-life extension domain, a first masking moiety, anda second masking moiety, the first masking moiety is linked to thecarboxy-terminus of the N-terminal spacer domain, and the firsthalf-life extension domain is linked to the amino-terminus of theN-terminal spacer domain. In some embodiments comprising a firsthalf-life extension domain, a second half-life extension domain, a firstmasking moiety, and a second masking moiety, the first masking moiety islinked to the amino-terminus of the C-terminal spacer domain, and thefirst half-life extension domain is linked to the carboxy-terminus ofthe C-terminal spacer domain. In some embodiments comprising a firsthalf-life extension domain, a second half-life extension domain, a firstmasking moiety, and a second masking moiety, the first masking moiety islinked to the carboxy-terminus of the C-terminal spacer domain, and thefirst half-life extension domain is linked to the amino-terminus of theC-terminal spacer domain.

In some embodiments comprising a first half-life extension domain, asecond half-life extension domain, a first masking moiety, and a secondmasking moiety, the second masking moiety is linked to theamino-terminus of the N-terminal spacer domain, and the cytokine orfunctional fragment thereof is linked to the carboxy-terminus of theN-terminal spacer domain. In some embodiments comprising a firsthalf-life extension domain, a second half-life extension domain, a firstmasking moiety, and a second masking moiety, the second masking moietyis linked to the carboxy-terminus of the N-terminal spacer domain, andthe cytokine or functional fragment thereof is linked to theamino-terminus of the N-terminal spacer domain. In some embodimentscomprising a first half-life extension domain, a second half-lifeextension domain, a first masking moiety, and a second masking moiety,the second masking moiety is linked to the amino-terminus of theC-terminal spacer domain, and the cytokine or functional fragmentthereof is linked to the carboxy-terminus of the C-terminal spacerdomain. In some embodiments comprising a first half-life extensiondomain, a second half-life extension domain, a first masking moiety, anda second masking moiety, the second masking moiety is linked to thecarboxy-terminus of the C-terminal spacer domain, and the cytokine orfunctional fragment thereof is linked to the amino-terminus of theC-terminal spacer domain.

In some embodiments comprising a first half-life extension domain, asecond half-life extension domain, a first masking moiety, and a secondmasking moiety, the second half-life extension domain is linked to theamino-terminus of the N-terminal spacer domain, and either the cytokineor functional fragment thereof or the second masking moiety is linked tothe carboxy-terminus of the N-terminal spacer domain. In someembodiments comprising a first half-life extension domain, a secondhalf-life extension domain, a first masking moiety, and a second maskingmoiety, the second half-life extension domain is linked to thecarboxy-terminus of the N-terminal spacer domain, and either thecytokine or functional fragment thereof or the second masking moiety islinked to the amino-terminus of the N-terminal spacer domain. In someembodiments comprising a first half-life extension domain, a secondhalf-life extension domain, a first masking moiety, and a second maskingmoiety, the second half-life extension domain is linked to theamino-terminus of the C-terminal spacer domain, and either the cytokineor functional fragment thereof or the second masking moiety is linked tothe carboxy-terminus of the C-terminal spacer domain. In someembodiments comprising a first half-life extension domain, a secondhalf-life extension domain, a first masking moiety, and a second maskingmoiety, the second half-life extension domain is linked to thecarboxy-terminus of the C-terminal spacer domain, and either thecytokine or functional fragment thereof or the second masking moiety islinked to the amino-terminus of the C-terminal spacer domain.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domainis linked to the second half-life extension domain via a linker. In someembodiments, the linker linking the first half-life extension domain andthe second half-life extension domain comprises an N-terminal spacerdomain and/or a C-terminal spacer domain. In some embodiments, thelinker linking the first half-life extension domain and the secondhalf-life extension domain comprises a cleavable peptide and anN-terminal spacer domain and/or a C-terminal spacer domain. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain that are linked together via a linker, thelinker comprises an amino-terminus and a carboxy terminus, and the firsthalf-life extension domain is linked to the amino-terminus of the linkerand the second half-life extension domain is linked to thecarboxy-terminus of the linker. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain thatare linked together via a linker, the linker comprises an amino-terminusand a carboxy terminus, and the first half-life extension domain islinked to the carboxy-terminus of the linker and the second half-lifeextension domain is linked to the amino-terminus of the linker.

In some embodiments, the N-terminal spacer domain comprises an aminoacid sequence selected from the group consisting of SEQ ID NOs: 20-95,235, 268, 269, 303-305, 323-338, 340, 341, 727, 794, and 799. In someembodiments, the C-terminal spacer domain comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 20-95, 235,268, 269, 303-305, 323-338, 340, 341, 727, 794, and 799. In someembodiments, the N-terminal spacer domain comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 20-95, 235,268, 269, 303-305, 323-338, 340, 341, 727, 794, and 799, and theC-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

In some embodiments, the N-terminal spacer domain comprises an aminoacid sequence selected from the group consisting of SEQ ID NOs: 20-95,235, 268, and 269. In some embodiments, the C-terminal spacer domaincomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 20-95, 235, 268, and 269. In some embodiments, theN-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, and 269, and theC-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, and 269. In someembodiments, the linker comprises an N-terminal spacer domain comprisingan amino acid sequence selected from the group consisting of SEQ ID NOs:20-95, 235, 268, and 269, and an C-terminal spacer domain comprising anamino acid sequence selected from the group consisting of SEQ ID NOs:20-95, 235, 268, and 269. In some embodiments, the linker comprises anN-terminal spacer domain comprising the amino acid sequence of SEQ IDNO: 268, and an C-terminal spacer domain comprising the amino acidsequence of SEQ ID NO: 269. In some embodiments, the linker comprises anN-terminal spacer domain comprising the amino acid sequence of SEQ IDNO: 268, a cleavable peptide comprising the amino acid sequence of SEQID NO: 264, and an C-terminal spacer domain comprising the amino acidsequence of SEQ ID NO: 269. In some embodiments, the linker comprises anN-terminal spacer domain comprising the amino acid sequence of SEQ IDNO: 269, and an C-terminal spacer domain comprising the amino acidsequence of SEQ ID NO: 268. In some embodiments, the linker comprises anN-terminal spacer domain comprising the amino acid sequence of SEQ IDNO: 269, a cleavable peptide comprising the amino acid sequence of SEQID NO: 264, and an C-terminal spacer domain comprising the amino acidsequence of SEQ ID NO: 268.

In some embodiments, the N-terminal spacer domain comprises an aminoacid sequence selected from the group consisting of SEQ ID NOs: 20-95,235, 268, and 269. In some embodiments, the N-terminal spacer domaincomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of any one of SEQ ID NOs:20-95, 235, 268, 269, 303-305, 323-338, 340, 341, 727, 794, and 799. Insome embodiments, the N-terminal spacer domain comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of any one of SEQ ID NOs: 20-95, 235, 268, and 269.In some embodiments, the C-terminal spacer domain comprises an aminoacid sequence having about or at least about 85%, 86%, 87%, 88%, 89%,90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity tothe amino acid sequence of any one of SEQ ID NOs: 20-95, 235, 268, 269,303-305, 323-338, 340, 341, 727, 794, and 799. In some embodiments, theC-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, and 269. In someembodiments, the C-terminal spacer domain comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of any one of SEQ ID NOs: 20-95, 235, 268, and 269.In some embodiments, the N-terminal spacer domain comprises an aminoacid sequence selected from the group consisting of SEQ ID NOs: 20-95,235, 268, and 269, and the C-terminal spacer domain comprises an aminoacid sequence selected from the group consisting of SEQ ID NOs: 20-95,235, 268, and 269. In some embodiments, the N-terminal spacer domaincomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of any one of SEQ ID NOs:20-95, 235, 268, and 269, and the C-terminal spacer domain comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of any one of SEQ ID NOs: 20-95,235, 268, and 269. In some embodiments, the N-terminal spacer domaincomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 268, and theC-terminal spacer domain comprises an amino acid sequence having aboutor at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to the amino acid sequence ofSEQ ID NO: 269. In some embodiments, the N-terminal spacer domaincomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 268, thecleavable peptide comprises the amino acid sequence of SEQ ID NO: 264,and the C-terminal spacer domain comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 269. Exemplary spacer domains (e.g., N-terminalspacer domains and/or C-terminal spacer domains) are shown in Table 2.

TABLE 2 Exemplary spacer domains PA (SEQ ID NO: 20)GGGGSGGGGSGGGGS (SEQ ID NO: 21) PSGPSAGGAA (SEQ ID NO: 22)GGPPASAGS (SEQ ID NO: 23) GSPPAGGAP (SEQ ID NO: 24)GPGSGSGGAA (SEQ ID NO: 25) GGGGSGGGGS (SEQ ID NO: 26)GGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 27) PGSGS (SEQ ID NO: 28)GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG (SEQ ID NO: 29)GGGGSGGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 30)GGGGSGGGGSGGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 31)GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 32)GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 33)GGSSPP (SEQ ID NO: 34) SGP (SEQ ID NO: 35) GSP (SEQ ID NO: 36)GSPP (SEQ ID NO: 37) GSPS (SEQ ID NO: 38) GPPSGSSP (SEQ ID NO: 39)GSSGGPPGG (SEQ ID NO: 40) SGSPSGSGGG (SEQ ID NO: 41)GPPGPPGSSG (SEQ ID NO: 42) SGGG (SEQ ID NO: 43)GSSSGPPGPPS (SEQ ID NO: 44) GGS (SEQ ID NO: 45) GGGSSGGS (SEQ ID NO: 46)GGSGG (SEQ ID NO: 47) GGGS (SEQ ID NO: 48) GS (SEQ ID NO: 48)GSGGGSSGGS (SEQ ID NO: 50) GSSGGS (SEQ ID NO: 51)GGGSSGGSG (SEQ ID NO: 52) GGSAGGS (SEQ ID NO: 53) GHS (SEQ ID NO: 54)GPS (SEQ ID NO: 55) GAS (SEQ ID NO: 56) SGG (SEQ ID NO: 57)SGGSGG (SEQ ID NO: 58) SSG (SEQ ID NO: 59) GGGSGG (SEQ ID NO: 60)GG (SEQ ID NO: 61) GGG (SEQ ID NO: 62) SHGG (SEQ ID NO: 63)HGGG (SEQ ID NO: 64) SGAA (SEQ ID NO: 65) SGPA (SEQ ID NO: 66)GGSGGS (SEQ ID NO: 67) GGSGGP (SEQ ID NO: 68) GGSGGG (SEQ ID NO: 69)GSGGPGPS (SEQ ID NO: 70) SGPPGSS (SEQ ID NO: 71) SSGGSGP (SEQ ID NO: 72)SSPSPSGG (SEQ ID NO: 73) SPGGSS (SEQ ID NO: 74) GGPGSSP (SEQ ID NO: 75)SGPPGGPSS (SEQ ID NO: 76) GPGPGSPPGGSS (SEQ ID NO: 77)SGPP (SEQ ID NO: 78) PGSPSSS (SEQ ID NO: 79) PSPGGPS (SEQ ID NO: 80)GGPPS (SEQ ID NO: 81) PSPPSS (SEQ ID NO: 82) SGGPGP (SEQ ID NO: 83)GPSPGS (SEQ ID NO: 84) GSPGPSP (SEQ ID NO: 85) PSSGGSS (SEQ ID NO: 86)SGSSGP (SEQ ID NO: 87) GGSSSPP (SEQ ID NO: 88) GSPGSP (SEQ ID NO: 89)PPPS (SEQ ID NO: 90) APPPS (SEQ ID NO: 91) AAPPPS (SEQ ID NO: 92)SAPPPS (SEQ ID NO: 93) SSGP (SEQ ID NO: 94) SSPGP (SEQ ID NO: 95)SGGSGGGGSGGGSGGGGSLQ (SEQ ID NO: 235) GSGP (SEQ ID NO: 268)GPAP (SEQ ID NO: 269) SGS (SEQ ID NO: 727) SG (SEQ ID NO: 794)GSG (SEQ ID NO: 799) PGPGP (SEQ ID NO: 323)SGGCGGHQYERRGGC (SEQ ID NO: 324) SGGCSGHQYERREGC (SEQ ID NO: 325)SGGCGGHYFERHGGC (SEQ ID NO: 326) SGGCSGHYFERHEGC (SEQ ID NO: 327)SGGCSFHQYERHEGC (SEQ ID NO: 328) PSGSS (SEQ ID NO: 329)GSPG (SEQ ID NO: 330) GGSPGG (SEQ ID NO: 331) GGPGGP (SEQ ID NO: 332)GGSG (SEQ ID NO: 333) GSPPGG (SEQ ID NO: 334) GPGSPG (SEQ ID NO: 335)GSSPPG (SEQ ID NO: 336) GGP (SEQ ID NO: 337) SGPGSGS (SEQ ID NO: 338)SGPGSGS (SEQ ID NO: 340) SGSGGSP (SEQ ID NO: 341)GGGSSP (SEQ ID NO: 303) SGGP (SEQ ID NO: 304) SGPSGSPG (SEQ ID NO: 305)

In some embodiments, the N-terminal spacer domain comprises an aminoacid sequence produced by modifying the amino acid sequence of any ofthe N-terminal spacer domains described herein. In some embodiments, theN-terminal spacer domain comprises an amino acid sequence produced bymodifying the amino acid sequence of any one of SEQ ID NOs: 20-95, 235,268, 269, 303-305, 323-338, 340, 341, 727, 794, and 799. In someembodiments, the C-terminal spacer domain comprises an amino acidsequence produced by modifying the amino acid sequence of any of theC-terminal spacer domains described herein. In some embodiments, theC-terminal spacer domain comprises an amino acid sequence produced bymodifying the amino acid sequence of any one of SEQ ID NOs: 20-95, 235,268, 269, 303-305, 323-338, 340, 341, 727, 794, and 799. In someembodiments, the N-terminal spacer domain comprises an amino acidsequence produced by modifying the amino acid sequence of any one of SEQID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340, 341, 727, 794, and799, and the C-terminal spacer domain comprises an amino acid sequenceproduced by modifying the amino acid sequence of any one of SEQ ID NOs:20-95, 235, 268, 269, 303-305, 323-338, 340, 341, 727, 794, and 799. Insome embodiments, the N-terminal spacer domain and/or the C-terminalspacer domain comprises the amino acid sequence of SEQ ID NO: 28.

In some embodiments, the N-terminal spacer domain and/or the C-terminalspacer domain consists of one or more amino acids. In some embodiments,the one or more amino acids of the N-terminal spacer domain and/or theC-terminal spacer domain are selected from the group consisting ofhydrophilic amino acids (e.g., lysine, arginine, histidine, asparticacid, glutamic acid, serine, threonine, asparagine, or glutamine),hydrophobic amino acids (e.g., alanine, valine, isoleucine, leucine,methionine, phenylalanine, tyrosine, tryptophan, cysteine, glycine, orproline), polar amino acids (e.g., serine, threonine, cysteine,asparagine, glutamine, or tyrosine), nonpolar amino acids (e.g.,glycine, alanine, valine, proline, leucine, isoleucine, methionine,tryptophan, or phenylalanine), amino acids with aliphatic side chains(e.g., glycine, alanine, valine, leucine, or isoleucine), amino acidswith hydroxyl-containing side chains (e.g., serine or threonine), aminoacids with sulfur-containing side chains (e.g., cysteine or methionine),charged amino acids (e.g., arginine, lysine, aspartic acid, or glutamicacid), uncharged amino acids (e.g., serine, threonine, asparagine, orglutamine), aromatic amino acids (e.g., tyrosine, tryptophan, orphenylalanine), cyclic amino acids (e.g., proline), acidic amino acids(e.g., aspartic acid, asparagine, glutamic acid, or glutamine), basicamino acids (e.g., histidine, lysine, or arginine), and bulky aminoacids (e.g., phenylalanine, tyrosine, or tryptophan). In someembodiments, the N-terminal spacer domain and/or the C-terminal spacerdomain consists of a glycine (G). In some embodiments, the N-terminalspacer domain and/or the C-terminal spacer domain consists of a glycine(G) and a proline (P), and has the amino acid sequence of GP or PG.

It is understood that a modification to a “spacer domain,” as describedin some embodiments, can refer to a modification to any one or more ofthe spacer domains described herein (e.g., any N-terminal spacer domainand/or any C-terminal spacer domain described herein). For example, amodification to a spacer domain can refer to (a) a modification to anyN-terminal spacer domain described herein, (b) a modification to anyC-terminal spacer domain described herein, or (c) a modification to anyN-terminal spacer domain and to any C-terminal spacer domain describedherein. As such, any of the linkers described herein that include anN-terminal spacer domain include embodiments where the N-terminal spacerdomain is modified in accordance with the modifications describedherein, any of the linkers described herein that include a C-terminalspacer domain include embodiments where the C-terminal spacer domain ismodified in accordance with the modifications described herein, and anyof the linkers described herein that include an N-terminal spacer domainand a C-terminal spacer domain include embodiments where the N-terminalspacer domain and/or the C-terminal spacer domain is/are modified inaccordance with the modifications described herein.

The modification to the sequence of the N-terminal spacer domain and/orthe C-terminal spacer domain can be any modification to the amino acidsequence of the spacer domain, including the incorporation of anyadditional amino acid into the sequence, the substitution of any aminoacid for a different amino acid, and/or the removal of any amino acidfrom the sequence.

In some embodiments, one or more additional amino acids are incorporatedby addition into to the amino acid sequence of the N-terminal spacerdomain and/or the C-terminal spacer domain. In some embodiments, the oneor more amino acids that are incorporated by addition into the aminoacid sequence of the N-terminal spacer domain and/or the C-terminalspacer domain are selected from the group consisting of hydrophilicamino acids (e.g., lysine, arginine, histidine, aspartic acid, glutamicacid, serine, threonine, asparagine, or glutamine), hydrophobic aminoacids (e.g., alanine, valine, isoleucine, leucine, methionine,phenylalanine, tyrosine, tryptophan, cysteine, glycine, or proline),polar amino acids (e.g., serine, threonine, cysteine, asparagine,glutamine, or tyrosine), nonpolar amino acids (e.g., glycine, alanine,valine, proline, leucine, isoleucine, methionine, tryptophan, orphenylalanine), amino acids with aliphatic side chains (e.g., glycine,alanine, valine, leucine, or isoleucine), amino acids withhydroxyl-containing side chains (e.g., serine or threonine), amino acidswith sulfur-containing side chains (e.g., cysteine or methionine),charged amino acids (e.g., arginine, lysine, aspartic acid, or glutamicacid), uncharged amino acids (e.g., serine, threonine, asparagine, orglutamine), aromatic amino acids (e.g., tyrosine, tryptophan, orphenylalanine), cyclic amino acids (e.g., proline), acidic amino acids(e.g., aspartic acid, asparagine, glutamic acid, or glutamine), basicamino acids (e.g., histidine, lysine, or arginine), and bulky aminoacids (e.g., phenylalanine, tyrosine, or tryptophan).

In some embodiments, one or more amino acids are substituted into theamino acid sequence of the N-terminal spacer domain and/or theC-terminal spacer domain. In some embodiments, the one or more aminoacids that are substituted into the amino acid sequence of the spacerdomain are selected from the group consisting of hydrophilic amino acids(e.g., lysine, arginine, histidine, aspartic acid, glutamic acid,serine, threonine, asparagine, or glutamine), hydrophobic amino acids(e.g., alanine, valine, isoleucine, leucine, methionine, phenylalanine,tyrosine, tryptophan, cysteine, glycine, or proline), polar amino acids(e.g., serine, threonine, cysteine, asparagine, glutamine, or tyrosine),nonpolar amino acids (e.g., glycine, alanine, valine, proline, leucine,isoleucine, methionine, tryptophan, or phenylalanine), amino acids withaliphatic side chains (e.g., glycine, alanine, valine, leucine, orisoleucine), amino acids with hydroxyl-containing side chains (e.g.,serine or threonine), amino acids with sulfur-containing side chains(e.g., cysteine or methionine), charged amino acids (e.g., arginine,lysine, aspartic acid, or glutamic acid), uncharged amino acids (e.g.,serine, threonine, asparagine, or glutamine), aromatic amino acids(e.g., tyrosine, tryptophan, or phenylalanine), cyclic amino acids(e.g., proline), acidic amino acids (e.g., aspartic acid, asparagine,glutamic acid, or glutamine), basic amino acids (e.g., histidine,lysine, or arginine), and bulky amino acids (e.g., phenylalanine,tyrosine, or tryptophan).

In some embodiments, the modification to the amino acid sequence of theN-terminal spacer domain and/or the C-terminal spacer domain comprisesthe substitution of at least one hydrophilic amino acid for ahydrophobic amino acid, the substitution of at least one hydrophobicamino acid for a hydrophilic amino acid, the substitution of at leastone polar amino acid for a nonpolar amino acid, the substitution of atleast one nonpolar amino acid for a polar amino acid, the substitutionof at least one charged amino acid for an uncharged amino acid, thesubstitution of at least one uncharged amino acid for a charged aminoacid, the substitution of at least one acidic amino acid for a basicamino acid, the substitution of at least one basic amino acid for anacidic amino acid, the substitution of at least one non-bulky amino acidfor a bulky amino acid, the substitution of at least one bulky aminoacid for a non-bulky amino acid, the substitution of at least one aminoacid with a hydroxyl-containing side chain or a sulfur-containing sidechain for an aliphatic amino acid, the substitution of at least oneamino acid with a hydroxyl-containing side chain or a sulfur-containingside chain for an aromatic amino acid, or the substitution of at leastone aromatic amino acid for an amino acid with a hydroxyl-containingside chain or a sulfur-containing side chain.

In some embodiments, the one or more amino acids that are removed fromthe amino acid sequence of the N-terminal spacer domain and/or theC-terminal spacer domain are selected from the group consisting ofhydrophilic amino acids (e.g., lysine, arginine, histidine, asparticacid, glutamic acid, serine, threonine, asparagine, or glutamine),hydrophobic amino acids (e.g., alanine, valine, isoleucine, leucine,methionine, phenylalanine, tyrosine, tryptophan, cysteine, glycine, orproline), polar amino acids (e.g., serine, threonine, cysteine,asparagine, glutamine, or tyrosine), nonpolar amino acids (e.g.,glycine, alanine, valine, proline, leucine, isoleucine, methionine,tryptophan, or phenylalanine), amino acids with aliphatic side chains(e.g., glycine, alanine, valine, leucine, or isoleucine), amino acidswith hydroxyl-containing side chains (e.g., serine or threonine), aminoacids with sulfur-containing side chains (e.g., cysteine or methionine),charged amino acids (e.g., arginine, lysine, aspartic acid, or glutamicacid), uncharged amino acids (e.g., serine, threonine, asparagine, orglutamine), aromatic amino acids (e.g., tyrosine, tryptophan, orphenylalanine), cyclic amino acids (e.g., proline), acidic amino acids(e.g., aspartic acid, asparagine, glutamic acid, or glutamine), basicamino acids (e.g., histidine, lysine, or arginine), and bulky aminoacids (e.g., phenylalanine, tyrosine, or tryptophan).

Any of the modifications to the spacer domains described herein (e.g.,any N-terminal spacer domain and/or any C-terminal spacer domain) can bemodifications made to the amino acid sequence of any of the N-terminalspacer domains and/or C-terminal spacer domains described herein,including any one of SEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338,340, 341, 727, 794, and 799. Any of the modifications to the spacerdomains described herein can be modifications made for any purpose. Forinstance, modifications to the N-terminal spacer domain and/or theC-terminal spacer domain of a linker that includes a cleavable peptidecan be made for the purpose of altering the conformation of the linkersuch that the efficiency of the cleavage of the cleavable peptide isaltered. Modifications to the N-terminal spacer domain and/or theC-terminal spacer domain of a linker that includes a cleavable peptidecan also be made for the purpose of altering the structure of a linkerthat includes a cleavable peptide such that cleavage efficiency of thecleavable peptide is altered under certain pH conditions.

D. Half-life Extension Domains

A long half-life in vivo is important for therapeutic proteins.Unfortunately, cytokines that are administered to a subject generallyhave a short half-life since they are normally cleared rapidly from thesubject by mechanisms including clearance by the kidney and endocyticdegradation. Thus, in some embodiments of the masked cytokine providedherein, a half-life extension domain is linked to the masked cytokinefor the purpose of extending the half-life of the cytokine in vivo.

In some embodiments, the masked cytokine provided herein comprises ahalf-life extension domain selected from the group consisting ofantibodies and fragments thereof, albumin, albumin-binding proteins,IgG-binding proteins, and polyamino acid sequences. It is contemplatedthat other mechanisms for extending the half-life of the masked cytokineavailable in the art may also be employed. The half-life extensiondomain comprises an amino-terminus and a carboxy-terminus.

In some embodiments, the masked cytokine comprises a half-life extensiondomain. In some embodiments, the masked cytokine comprises a singlehalf-life extension domain. In some embodiments, the masked cytokinecomprises more than one half-life extension domain, each of which can beany of the half-life extension domains described herein. In someembodiments, the masked cytokine comprises a first half-life extensiondomain and a second half-life extension domain. It is understood thatreference to “a half-life extension domain” or “the half-life extensiondomain” can refer to the half-life extension domain in a masked cytokinecomprising a single half-life extension domain, or it can refer to thefirst half-life extension domain in a masked cytokine comprising a firsthalf-life extension domain and a second half-life extension domain, orit can refer to the second half-life extension domain in a maskedcytokine comprising a first half-life extension domain and a secondhalf-life extension domain, or it can refer to the first half-lifeextension domain and the second half-life extension domain in a maskedcytokine comprising a first half-life extension domain and a secondhalf-life extension domain.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domainis linked to the second half-life extension domain. In some embodimentscomprising a first half-life extension domain and a second half-lifeextension domain, the first half-life extension domain is linked to thesecond half-life extension domain via a linker. The first half-lifeextension domain and the second half-life extension domain that arelinked can, in some embodiments, each be any half-life extension domaindescribed herein. For instance, in some embodiments, the first half-lifeextension domain and/or the second half-life extension domain of thelinked first and second half-life extension domains is an Fc domain orfragment thereof. In some embodiments, the first half-life extensiondomain and/or the second half-life extension domain of the linked firstand second half-life extension domains is an antibody, or a fragment,variant, or derivative thereof.

1. Antibodies and Fragments Thereof

By linking a masked cytokine to an antibody or fragment thereof that iscapable of FcRn-mediated recycling, clearance of the masked cytokinefrom a subject can be reduced or otherwise delayed, thereby prolongingthe half-life of the administered masked cytokine.

In some embodiments of the masked cytokine, the half-life extensiondomain comprises an antibody or fragment thereof. In some embodiments,the masked cytokine comprises more than one antibody or fragmentthereof, each of which can be any of the antibodies or fragments thereofdescribed herein. In some embodiments, the masked cytokine comprises afirst half-life extension domain and a second half-life extensiondomain, each of which comprises an antibody or fragment thereof. It isunderstood that reference to “an antibody or fragment thereof” or “theantibody or fragment thereof” can refer to the antibody or fragmentthereof of the half-life extension domain in a masked cytokinecomprising a single half-life extension domain, or it can refer to theantibody or fragment thereof of the first half-life extension domain ina masked cytokine comprising a first half-life extension domain and asecond half-life extension domain, or it can refer to the antibody orfragment thereof of the second half-life extension domain in a maskedcytokine comprising a first half-life extension domain and a secondhalf-life extension domain, or it can refer to the antibody or fragmentthereof of the first half-life extension domain and the antibody orfragment thereof of the second half-life extension domain in a maskedcytokine comprising a first half-life extension domain and a secondhalf-life extension domain.

The antibody or fragment thereof can be any antibody or fragmentthereof. In some embodiments, the antibody or fragment thereof is anyantibody or fragment thereof that is capable of FcRn-mediated recycling,such as any heavy chain polypeptide or portion thereof (e.g., Fc domainor fragment thereof) that is capable of FcRn-mediated recycling.However, in some embodiments of a masked cytokine comprising a firsthalf-life extension domain and a second half-life extension domain,either the first half-life extension domain or the second half-lifeextension domain may comprise an antibody or fragment thereof that doesnot bind to the FcRn receptor, such as a light chain polypeptide. Forexample, in some embodiments of the masked cytokine, a first half-lifeextension domain comprises an antibody or fragment thereof thatcomprises a light chain polypeptide or portion thereof that does notdirectly interact with the FcRn receptor, but the masked cytokinenonetheless has an extended half-life due to comprising a secondhalf-life extension domain that is capable of interacting with the FcRnreceptor, such as by comprising a heavy chain polypeptide. It isrecognized in the art that FcRn-mediated recycling requires binding ofthe FcRn receptor to the Fc region of the antibody or fragment thereof.For instance, studies have shown that residues 1253, 5254, H435, andY436 (numbering according to the Kabat EU index numbering system) areimportant for the interaction between the human Fc region and the humanFcRn complex. See, e.g., Firan, M., et al., Int. Immunol. 13 (2001)993-1002; Shields, R. L., et al, J. Biol. Chem. 276 (2001) 6591-6604).Various mutants of residues 248-259, 301-317, 376-382, and 424-437(numbering according to the Kabat EU index numbering system) have alsobeen examined and reported. Yeung, Y. A., et al. (J. Immunol. 182 (2009)7667-7671.

In some embodiments, the antibody or fragment thereof comprises either aheavy chain polypeptide or a light chain polypeptide. In someembodiments, the antibody or fragment thereof comprises a portion ofeither a heavy chain polypeptide or a light chain polypeptide. In someembodiments, the antibody or fragment thereof comprises an Fc domain orfragment thereof. In some embodiments, the antibody or fragment thereofcomprises a CH2 and CH3 domain or a fragment thereof. In someembodiments, the antibody or fragment thereof comprises the constantdomain of the heavy chain polypeptide. In some embodiments, the antibodyor fragment thereof comprises the constant domain of the light chainpolypeptide. In some embodiments, the antibody or fragment thereofcomprises a heavy chain polypeptide or fragment thereof (e.g., an Fcdomain or fragment thereof). In some embodiments, the antibody orfragment thereof comprises a light chain polypeptide.

In some embodiments, the heavy chain polypeptide comprises the aminoacid sequence of SEQ ID NO: 158. In some embodiments, the light chainpolypeptide comprises the amino acid sequence of SEQ ID NO: 157. In someembodiments, the heavy chain polypeptide comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 158. In some embodiments, the heavychain polypeptide comprises the amino acid sequence of SEQ ID NO: 168.In some embodiments, the heavy chain polypeptide comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 168. In some embodiments, the heavychain polypeptide comprises the amino acid sequence of SEQ ID NO: 169.In some embodiments, the heavy chain polypeptide comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 169.

In some embodiments, the light chain polypeptide comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 157. In some embodiments, the lightchain polypeptide comprises the amino acid sequence of SEQ ID NO: 170.In some embodiments, the light chain polypeptide comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 170.

In some embodiments, the antibody of fragment thereof comprises an Fcdomain or fragment thereof. In some embodiments, the antibody offragment thereof is an Fc domain or fragment thereof.

In some embodiments, the Fc domain or fragment thereof comprises anamino acid sequence selected from the group consisting of SEQ ID NOs:616, 619, 622, 625, 721, 772-774, 793, and 796. In some embodiments, theFc domain or fragment thereof comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to an amino acidsequence selected from the group consisting of SEQ ID NOs: 616, 619,622, 625, 721, 772-774, 793, and 796. In some embodiments, the Fc domainor fragment thereof comprises the amino acid sequence of SEQ ID NO: 154.In some embodiments, the Fc domain or fragment thereof comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 154. In someembodiments, the Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 155. In some embodiments, the Fc domain orfragment thereof comprises an amino acid sequence having about or atleast about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, or 99% sequence identity to the amino acid sequence of SEQ IDNO: 155. In some embodiments, the Fc domain or fragment thereofcomprises the amino acid sequence of SEQ ID NO: 156. In someembodiments, the Fc domain or fragment thereof comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 156. In some embodiments, the Fcdomain or fragment thereof comprises the amino acid sequence of SEQ IDNO: 265. In some embodiments, the Fc domain or fragment thereofcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 265. In someembodiments, the Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 155. In some embodiments, the Fc domain orfragment thereof comprises an amino acid sequence having about or atleast about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%,97%, 98%, or 99% sequence identity to the amino acid sequence of SEQ IDNO: 155. In some embodiments, the Fc domain or fragment thereofcomprises the amino acid sequence of SEQ ID NO: 772, or comprises anamino acid sequence having about or at least about 85%, 86%, 87%, 88%,89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 772. In someembodiments, the Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 773, or comprises an amino acid sequence havingabout or at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%,94%, 95%, 96%, 97%, 98%, or 99% sequence identity to the amino acidsequence of SEQ ID NO: 773. In some embodiments, the Fc domain orfragment thereof comprises the amino acid sequence of SEQ ID NO: 774, orcomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 774.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence selected from the group consisting of SEQ ID NOs: 154-156, 265,616, 619, 622, 625, 721, 772-774, 793, and 796, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence selected from the group consisting of SEQ ID NOs:154-156, 265, 616, 619, 622, 625, 721, 772-774, 793, and 796. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:154-156, 265, 616, 619, 622, 625, 721, 772-774, 793, and 796, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising an amino acid sequence having about or at least about85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or99% sequence identity to an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 154-156, 265, 616, 619, 622, 625, 721,772-774, 793, and 796. In some embodiments comprising a first half-lifeextension domain and a second half-life extension domain, the firsthalf-life extension domain comprises the amino acid sequence of any ofthe first half-life extension domains listed in Tables 4-11, and thesecond half-life extension domain comprises the amino acid sequence ofany of the first half-life extension domains listed in Tables 4-11.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 155, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 155. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 155, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 156. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 156, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 155.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 155, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 616. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 616, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 155. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 155, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 616. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 616, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 155.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 265. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 265, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 265, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 156. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 156, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 265.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 155. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 155, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 155, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 156. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 156, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 155.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 721, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 619. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 619, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 721. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 619, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 721. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 721, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 619.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 721, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 772. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 772, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 721. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 772, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 721. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 721, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 772.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 793, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 622. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 622, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 793. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 622, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 793. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 793, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 622.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 793, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 773. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 773, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 793. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 773, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 793. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 793, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 773.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 796, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 625. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 625, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 796. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 625, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 796. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 796, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 625.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 796, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 774. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 774, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 796. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 774, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 796. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 796, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 774.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 793, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 773. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 774 and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 793. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 773, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 793. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 793, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 773.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 796, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 774. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 774, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 796. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 774, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 796. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 796, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 774.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 155. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 155, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156 In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 155, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 156. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 156, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 155.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 772, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 721. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 721, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 772. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 721, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 772. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 772, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 721.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 156, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 156. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 156, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 156.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 157, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 158. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 158, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 157. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 157, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 158. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 158, and the second half-lifeextension domain comprises an Fc domain or fragment thereof comprisingan amino acid sequence having about or at least about 85%, 86%, 87%,88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequenceidentity to the amino acid sequence of SEQ ID NO: 157.

In some embodiments, the Fc domain or fragment thereof comprises theamino acid sequence of SEQ ID NO: 168. In some embodiments, the Fcdomain or fragment thereof comprises an amino acid sequence having aboutor at least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to the amino acid sequence ofSEQ ID NO: 168. In some embodiments, the Fc domain or fragment thereofcomprises the amino acid sequence of SEQ ID NO: 169. In someembodiments, the Fc domain or fragment thereof comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 169.

In some embodiments, a half-life extension domain comprises an aminoacid sequence produced by introducing one or more modifications to theamino acid sequence of the half-life extension domain, such as byintroducing one or more amino acid substitutions, additions, ordeletions to the amino acid sequence of any one of SEQ ID NOs: 154-158,168-170, 265, 616, 619, 622, 625, 721, 772-774, 793, and 796, or to anyone of the amino acid sequences of the half-life extension domaindescribed herein. The one or more modifications can be any modificationsor alterations described herein, including, in some embodiments, anymodifications or alterations disclosed herein that promoteheterodimerization of polypeptide chains and/or suppresseshomodimerization of polypeptide chains, alter effector function, orenhance effector function.

In some embodiments, the half-life extension domain comprises a heavychain polypeptide that comprises one or more amino acid substitutionsaltering effector function. In some embodiments, the half-life extensiondomain is an IgG1 heavy chain polypeptide and comprises the aminosubstitution(s): N297A, N297G, or N297Q; L234A and L235A; C220S, C226S,C229S, and P238S; C226S, C229S, E233P, L234V, and L235A; L234F, L235E,and P331S; S267E and L328F; D265A; and/or L234A, L235A, and P329G,numbered according to the Kabat EU numbering system. In someembodiments, the half-life extension domain is an IgG1 heavy chainpolypeptide and comprises one or more amino acid substitutions selectedfrom the group consisting of N297A, N297G, N297Q, L234A, L235A, C220S,C226S, C229S, P238S, E233P, L234V, L234F, L235E, P331S, S267E, L328F,D265A, and P329G, numbered according to the Kabat EU numbering system.In some embodiments, the half-life extension domain is an IgG2 heavychain polypeptide and comprises the amino substitution(s): V234A andG237A; H268Q, V309L, A330S, and A331S; or V234A, G237A, P238S, H268A,V309L, and A330S, numbered according to the Kabat EU numbering system.In some embodiments, the half-life extension domain is an IgG2 heavychain polypeptide and comprises one or more amino acid substitutionsselected from the group consisting of V234A, G237A, H268Q, V309L, A330S,A331S, P238S, H268A, and V309L, numbered according to the Kabat EUnumbering system. In some embodiments, the half-life extension domain isan IgG4 heavy chain polypeptide and comprises the amino substitution(s):L235A, G237A, and E318A; S228P, L234A, and L235A; H268Q, V309L, A330S,and P331S; and/or S228P and L235A, numbered according to the Kabat EUnumbering system. In some embodiments, the half-life extension domain isan IgG2 heavy chain polypeptide and comprises one or more amino acidsubstitutions selected from the group consisting of L235A, G237A, E318A,S228P, L234A, H268Q, V309L, A330S, and P331S, numbered according to theKabat EU numbering system.

In some embodiments, the half-life extension domain comprises a heavychain polypeptide that comprises one or more amino acid substitutionsenhancing effector function. In some embodiments, the half-lifeextension domain is an IgG1 heavy chain polypeptide and comprises theamino acid substitution(s): S298A, E333A, and K334A; S239D and I332E;S239D, A330L, and I332E; P247I and A339D or A339Q; D280H and K290S;D280H, K290S, and either S298D or S298V; F243L, R292P, and Y300L; F243L,R292P, Y300L, and P396L; F243L, R292P, Y300L, V305I, and P396L; G236A,S239D, and I332E; K326A and E333A; K326W and E333S; K290E, S298G, andT299A; K290E, S298G, T299A, and K326E; K290N, S298G, and T299A; K290N,S298G, T299A, and K326E; K334V; L235S, S239D, and K334V; K334V andQ331M, S239D, F243V, E294L, or S298T; E233L, Q311M, and K334V; L234I,Q311M, and K334V; K334V and S298T, A330M, or A330F; K334V, Q311M, andeither A330M or A330F; K334V, S298T, and either A330M or A330F; K334V,S239D, and either A330M or S298T; L234Y, Y296W, and K290Y, F243V, orE294L; Y296W and either L234Y or K290Y; S239D, A330S, and I332E, V264I;F243L and V264I; L328M; I332E; L328M and I332E; V264I and I332E; S239Eand I332E; S239Q and I332E; S239E; A330Y; I332D; L328I and I332E; L328Qand I332E; V264T; V240I; V266I; S239D; S239D and I332D; S239D and I332N;S239D and I332Q; S239E and I332D; S239E and I332N; S239E and I332Q;S239N and I332D; S239N and I332E; S239Q and I332D; A330Y and I332E;V264I, A330Y, and I332E; A330L and I332E; V264I, A330L, and I332E;L234E, L234Y, or L234I; L235D, L235S, L235Y, or L235I; S239T; V240M;V264Y; A330I; N325T; I332E and L328D, L328V, L328T, or L328I; V264I,I332E, and either S239E or S239Q; S239E, V264I, A330Y, and I332E; A330Y,I332E, and either S239D or S239N; A330L, I332E, and either S239D orS239N; V264I, S298A, and I332E; S298A, I332E, and either S239D or S239N;S239D, V264I, and I332E; S239D, V264I, S298A, and I332E; S239D, V264I,A330L, and I332E; S239D, I332E, and A330I; P230A; P230A, E233D, andI332E; E272Y; K274T, K274E, K274R, K274L, or K274Y; F275W; N276L; Y278T;V302I; E318R; S324D, S324I or S324V; K326I or K326T; T335D, T335R, orT335Y; V240I and V266I; S239D, A330Y, I332E, and L234I; S239D, A330Y,I332E, and L235D; S239D, A330Y, I332E, and V240I; S239D, A330Y, I332E,and V264T; and/or S239D, A330Y, I332E, and either K326E or K326T,numbered according to the Kabat EU numbering system. In someembodiments, the half-life extension domain is an IgG1 heavy chainpolypeptide and comprises one or more amino acid substitution(s)selected from the group consisting of: P230A, E233D, L234E, L234Y,L234I, L235D, L235S, L235Y, L235I, S239D, S239E, S239N, S239Q, S239T,V240I, V240M, F243L, V264I, V264T, V264Y, V266I, E272Y, K274T, K274E,K274R, K274L, K274Y, F275W, N276L, Y278T, V302I, E318R, S324D, S324I,S324V, N325T, K326I, K326T, L328M, L328I, L328Q, L328D, L328V, L328T,A330Y, A330L, A330I, I332D, I332E, I332N, I332Q, T335D, T335R, andT335Y.

In some embodiments, the half-life extension domain comprises an Fcdomain or fragment thereof that comprises one or more amino acidsubstitutions altering effector function. In some embodiments, thehalf-life extension domain is an IgG1 Fc domain or fragment thereof andcomprises the amino substitution(s): N297A, N297G, or N297Q; L234A andL235A; C220S, C226S, C229S, and P238S; C226S, C229S, E233P, L234V, andL235A; L234F, L235E, and P331S; S267E and L328F; D265A; and/or L234A,L235A, and P329G, numbered according to the Kabat EU numbering system.In some embodiments, the half-life extension domain is an IgG1 Fc domainor fragment thereof and comprises one or more amino acid substitutionsselected from the group consisting of N297A, N297G, N297Q, L234A, L235A,C220S, C226S, C229S, P238S, E233P, L234V, L234F, L235E, P331S, S267E,L328F, D265A, and P329G, numbered according to the Kabat EU numberingsystem. In some embodiments, the half-life extension domain is an IgG2Fc domain or fragment thereof and comprises the amino substitution(s):V234A and G237A; H268Q, V309L, A330S, and A331S; and/or V234A, G237A,P238S, H268A, V309L, and A330S, numbered according to the Kabat EUnumbering system. In some embodiments, the half-life extension domain isan IgG2 Fc domain or fragment thereof and comprises one or more aminoacid substitutions selected from the group consisting of V234A, G237A,H268Q, V309L, A330S, A331S, P238S, H268A, and V309L, numbered accordingto the Kabat EU numbering system. In some embodiments, the half-lifeextension domain is an IgG4 Fc domain or fragment thereof and comprisesthe amino substitution(s): L235A, G237A, and E318A; S228P, L234A, andL235A; H268Q, V309L, A330S, and P331S; and/or S228P and L235A, numberedaccording to the Kabat EU numbering system. In some embodiments, thehalf-life extension domain is an IgG2 Fc domain or fragment thereof andcomprises one or more amino acid substitutions selected from the groupconsisting of L235A, G237A, E318A, S228P, L234A, H268Q, V309L, A330S,and P331S, numbered according to the Kabat EU numbering system.

In some embodiments, the half-life extension domain comprises Fc domainor fragment thereof that comprises one or more amino acid substitutionsenhancing effector function. In some embodiments, the half-lifeextension domain is an IgG1 Fc domain or fragment thereof and comprisesthe amino acid substitution(s): S298A, E333A, and K334A; S239D andI332E; S239D, A330L, and I332E; P247I and A339D or A339Q; D280H andK290S; D280H, K290S, and either S298D or S298V; F243L, R292P, and Y300L;F243L, R292P, Y300L, and P396L; F243L, R292P, Y300L, V305I, and P396L;G236A, S239D, and I332E; K326A and E333A; K326W and E333S; K290E, S298G,and T299A; K290E, S298G, T299A, and K326E; K290N, S298G, and T299A;K290N, S298G, T299A, and K326E; K334V; L235S, S239D, and K334V; K334Vand Q331M, S239D, F243V, E294L, or S298T; E233L, Q311M, and K334V;L234I, Q311M, and K334V; K334V and S298T, A330M, or A330F; K334V, Q311M,and either A330M or A330F; K334V, S298T, and either A330M or A330F;K334V, S239D, and either A330M or S298T; L234Y, Y296W, and K290Y, F243V,or E294L; Y296W and either L234Y or K290Y; S239D, A330S, and I332E,V264I; F243L and V264I; L328M; I332E; L328M and I332E; V264I and I332E;S239E and I332E; S239Q and I332E; S239E; A330Y; I332D; L328I and I332E;L328Q and I332E; V264T; V240I; V266I; S239D; S239D and I332D; S239D andI332N; S239D and I332Q; S239E and I332D; S239E and I332N; S239E andI332Q; S239N and I332D; S239N and I332E; S239Q and I332D; A330Y andI332E; V264I, A330Y, and I332E; A330L and I332E; V264I, A330L, andI332E; L234E, L234Y, or L234I; L235D, L235S, L235Y, or L235I; S239T;V240M; V264Y; A330I; N325T; I332E and L328D, L328V, L328T, or L328I;V264I, I332E, and either S239E or S239Q; S239E, V264I, A330Y, and 1332E;A330Y, 1332E, and either S239D or S239N; A330L, 1332E, and either S239Dor S239N; V264I, S298A, and I332E; S298A, I332E, and either S239D orS239N; S239D, V264I, and I332E; S239D, V264I, S298A, and I332E; S239D,V264I, A330L, and I332E; S239D, I332E, and A330I; P230A; P230A, E233D,and I332E; E272Y; K274T, K274E, K274R, K274L, or K274Y; F275W; N276L;Y278T; V302I; E318R; S324D, S324I or S324V; K326I or K326T; T335D,T335R, or T335Y; V240I and V266I; S239D, A330Y, I332E, and L234I; S239D,A330Y, I332E, and L235D; S239D, A330Y, I332E, and V240I; S239D, A330Y,I332E, and V264T; and/or S239D, A330Y, I332E, and either K326E or K326T,numbered according to the Kabat EU numbering system. In someembodiments, the half-life extension domain is an IgG1 Fc domain orfragment thereof and comprises one or more amino acid substitution(s)selected from the group consisting of: P230A, E233D, L234E, L234Y,L234I, L235D, L235S, L235Y, L235I, S239D, S239E, S239N, S239Q, S239T,V240I, V240M, F243L, V264I, V264T, V264Y, V266I, E272Y, K274T, K274E,K274R, K274L, K274Y, F275W, N276L, Y278T, V302I, E318R, S324D, S324I,S324V, N325T, K326I, K326T, L328M, L328I, L328Q, L328D, L328V, L328T,A330Y, A330L, A330I, I332D, I332E, I332N, I332Q, T335D, T335R, andT335Y.

In some embodiments, the half-life extension domain comprises one ormore amino acid substitution(s) that enhance binding of the half-lifeextension domain to FcRn. In some embodiments, the one or more aminoacid substitution(s) increase binding affinity of an Fc-containingpolypeptide (e.g., a heavy chain polypeptide or an Fc domain or fragmentthereof) to FcRn at acidic pH. In some embodiments, the half-lifeextension domain comprises one or more amino acid substitution(s)selected from the group consisting of M428L; T250Q and M428L; M252Y,S254T, and T256E; P257I and N434H; D376V and N434H; P257I and Q3111;N434A; N434W; M428L and N434S; V259I and V308F; M252Y, S254T, and T256E;V259I, V308F and M428L; T307Q and N434A; T307Q and N434S; T307Q, E380A,and N434A; V308P and N434A; N434H; and V308P.

In some embodiments, the masked cytokine is a dimer is that is formed bythe half-life extension domain of one copy of the masked cytokineforming a disulfide bond with the corresponding half-life extensiondomain of a second copy of the masked cytokine.

2. Albumin

Albumin (also referred to herein as human serum albumin (HSA)) is anatural carrier protein that has an extended serum half-life ofapproximately three weeks due to its size and its susceptibility toFcRn-mediated recycling, which prevents intracellular degradation. Thus,linking a masked cytokine to albumin can greatly extend the half-life ofthe masked cytokine. This approach has been taken to extend the plasmahalf-life of therapeutically beneficial proteins. See, e.g., WO2001/079271A1 and WO 2003/59934A2, the contents of which are hereinincorporated by reference. HSA in its mature form is a polypeptide of585 amino acids as shown in SEQ ID NO: 171.

In some embodiments, the masked cytokine comprises a half-life extensiondomain that comprises an albumin polypeptide or a fragment or variantthereof (hereinafter referred to as “albumin” or “albumin polypeptide”).As used herein, the terms “albumin” and “albumin polypeptide” includesfragments of albumin as well as variants of albumin. The albuminpolypeptide comprises an amino-terminus and a carboxy-terminus. Thealbumin polypeptide can be any albumin polypeptide, including anyfragment or variant thereof, such as any albumin polypeptide describedin WO 2001/079271A1; WO 2003/59934A2; US20160152686A1; WO 2012/059486;WO 2011/124718; US20070048282, the contents of which are hereinincorporated by reference. In some embodiments, the albumin polypeptideis HSA.

In some embodiments of the masked cytokine, the half-life extensiondomain comprises an albumin polypeptide. In some embodiments, the maskedcytokine comprises more than one albumin polypeptide, each of which canbe any of the albumin polypeptides described herein. In someembodiments, the masked cytokine comprises a first half-life extensiondomain and a second half-life extension domain, each of which comprisesan albumin polypeptide. It is understood that reference to “an albuminpolypeptide” or “the albumin polypeptide” can refer to the albuminpolypeptide of the half-life extension domain in a masked cytokinecomprising a single half-life extension domain, or it can refer to thealbumin polypeptide of the first half-life extension domain in a maskedcytokine comprising a first half-life extension domain and a secondhalf-life extension domain, or it can refer to the albumin polypeptideof the second half-life extension domain in a masked cytokine comprisinga first half-life extension domain and a second half-life extensiondomain, or it can refer to the albumin polypeptide of the firsthalf-life extension domain and the albumin polypeptide of the secondhalf-life extension domain in a masked cytokine comprising a firsthalf-life extension domain and a second half-life extension domain.

In some embodiments, the albumin polypeptide is linked to a maskingmoiety. In some embodiments, a masking moiety is linked to theamino-terminus or the carboxy-terminus of the albumin polypeptide. Insome embodiments, the albumin polypeptide is linked to a masking moietyvia a linker. In some embodiments, a linker is linked to theamino-terminus or the carboxy-terminus of the albumin polypeptide. Insome embodiments, an N-terminal spacer domain or a C-terminal spacerdomain of the linker is linked to the amino-terminus or thecarboxy-terminus of the albumin polypeptide. In some embodiments, acleavable peptide of the linker is linked to the amino-terminus or thecarboxy-terminus of the albumin polypeptide. In some embodiments, thealbumin polypeptide is linked to a cytokine or functional fragmentthereof. In some embodiments, a cytokine or functional fragment thereofis linked to the amino-terminus or the carboxy-terminus of the albuminpolypeptide. In some embodiments, the albumin polypeptide is linked to acytokine or functional fragment thereof via a linker. In someembodiments, a linker is linked to the amino-terminus or thecarboxy-terminus of the albumin polypeptide.

In some embodiments, the albumin polypeptide comprises the amino acidsequence of SEQ ID NO: 171. In some embodiments, the albumin polypeptidecomprises an amino acid sequence having about or at least about 85%,86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%sequence identity to the amino acid sequence of SEQ ID NO: 171.

In some embodiments, the albumin polypeptide is a variant of albuminconsisting of a fragment of HSA (optionally with one or more amino acidmodifications). In some embodiments, the fragment of HSA is a fragmentof wildtype HSA. In some embodiments, the albumin polypeptide comprisesHSA domain 1 (amino acid residues 1-194 of SEQ ID NO: 171), HSA domain 2(amino acid residues 195-387 of SEQ ID NO: 171), HSA domain 3 (aminoacid residues 388-585), HSA domains 1 and 2, HSA domains 2 and 3, HSAdomains 1 and 3, or two copies of HSA domain 3. In some embodiments, thealbumin polypeptide consists of HSA domain 1 (amino acid residues 1-194of SEQ ID NO: 171), HSA domain 2 (amino acid residues 195-387 of SEQ IDNO: 171), HSA domain 3 (amino acid residues 388-585), HSA domains 1 and2, HSA domains 2 and 3, HSA domains 1 and 3, or two copies of HSA domain3.

In some embodiments, the albumin polypeptide comprises amino acidresidues 1-194 of SEQ ID NO: 171. In some embodiments, the albuminpolypeptide comprises amino acid residues 195-387 of SEQ ID NO: 171. Insome embodiments, the albumin polypeptide comprises amino acid residues388-585 of SEQ ID NO: 171. In some embodiments, the albumin polypeptidecomprises amino acid residues 1-387 of SEQ ID NO: 171. In someembodiments, the albumin polypeptide comprises amino acid residues195-585 of SEQ ID NO: 171. In some embodiments, the albumin polypeptidecomprises amino acid residues 1-105 of SEQ ID NO: 171. In someembodiments, the albumin polypeptide comprises amino acid residues120-194 of SEQ ID NO: 171. In some embodiments, the albumin polypeptidecomprises amino acid residues 195-291 of SEQ ID NO: 171. In someembodiments, the albumin polypeptide comprises amino acid residues316-387 of SEQ ID NO: 171. In some embodiments, the albumin polypeptidecomprises amino acid residues 388-491 of SEQ ID NO: 171. In someembodiments, the albumin polypeptide comprises amino acid residues512-585 of SEQ ID NO: 171. In some embodiments, the albumin polypeptidecomprises amino acid residues 1-194 and 388-585 of SEQ ID NO: 171. Insome embodiments, the albumin polypeptide comprises two copies of aminoacid residues 388-585 of SEQ ID NO: 171.

In some embodiments, the albumin polypeptide comprises an amino acidsequence produced by one or more amino acid modifications to the aminoacid sequence of any of the embodiments of the albumin polypeptidedescribed herein. In some embodiments, the albumin polypeptide comprisesan amino acid sequence comprising one or more amino acid modificationsthat increase the half-life of the albumin polypeptide in serum.Exemplary amino acid modifications that increase the half-life of thealbumin polypeptide in serum include amino acid substitutions made toE492, N503, D550, and/or K573 of HSA. In some embodiments, the albuminpolypeptide comprises one or more amino acid modifications that increasethe affinity of the albumin polypeptide for the FcRn receptor. Exemplaryamino acid modifications that increase the affinity of the albuminpolypeptide for the FcRn receptor include V418M, T420A, E505G, andV547A. In some embodiments, the albumin polypeptide comprises an aminoacid sequence produced by one or more amino acid modifications to theamino acid sequence of SEQ ID NO: 171. In some embodiments, the albuminpolypeptide comprises an amino acid sequence produced by one or moreamino acid modifications to the amino acid sequence of SEQ ID NO: 171.In some embodiments, the one or more amino acid modifications to theamino acid sequence of any of the albumin polypeptides described hereinis/are selected from the group consisting of Q417A, H440Q, H464Q, A490D,E492G/T/P/H, V493P/L, D494N/Q/A/E/P, E495Q/A, T496A, P499A,K500E/G/D/A/S/C/P/H/F/N/W/T/M/Y/V/Q/L/I/R, E501A/P/Q, N503K/D/H, A504E,E505K/D, T506F/S, H510Q, H535Q, K536A, P537A, K538A/H, T540S,K541A/D/G/N/E, E542P/D, D550N,K573Y/W/P/H/F/V/I/T/N/S/G/M/C/A/E/Q/R/L/D, K574N, Q580K, L575F, A577T/E,A578R/S, S579C/T, Q580K, A581D, A582T, and G584A. In some embodiments,the one or more amino acid modifications to the amino acid sequence ofany of the albumin polypeptides described herein is/are selected fromthe group consisting of V418M, T420A, E505G, and V547A.

3. Binding Proteins

Additional strategies for extending the half-life of masked cytokines inserum include linking the masked cytokine to certain binding proteins,such as albumin-binding proteins or IgG-binding proteins. The bindingproteins can be any protein that binds to a serum protein having aprolonged half-life, such as albumin or IgG. Albumin and IgG arepolypeptides that are known to have long half-lives in serum. Sincealbumin-binding proteins bind to, or otherwise associate with, albuminin serum, masked cytokines that are linked to an albumin-binding proteincan exhibit an extended half-life in serum. Likewise, since IgG-bindingproteins bind, or otherwise associate with, IgG in serum, maskedcytokines that are linked to an IgG-binding protein can exhibit anextended half-life in serum.

Albumin-binding proteins and methods by which they are linked toproteins of interest are described, for example, in WO 1991/01743, WO2001/45746, WO 2002/076489, WO 2004/041865, or US20070269422A1, thecontents of which are herein incorporated by reference.

In some embodiments, the half-life extension domain comprises analbumin-binding protein. The albumin-binding protein can be any of thealbumin-binding proteins described, for instance, in WO1991/01743,WO2001/45746, WO2002/076489, WO2004/041865, US20070269422A1;US20160152686A1; Dennis et al. (2002), JBC 277(38): 35035-35043.

In some embodiments of the masked cytokine, the half-life extensiondomain comprises an albumin-binding protein. In some embodiments, themasked cytokine comprises more than one albumin-binding protein, each ofwhich can be any of the albumin-binding proteins described herein. Insome embodiments, the masked cytokine comprises a first half-lifeextension domain and a second half-life extension domain, each of whichcomprises an albumin-binding protein. It is understood that reference to“an albumin-binding protein” or “the albumin-binding protein” can referto the albumin-binding protein of the half-life extension domain in amasked cytokine comprising a single half-life extension domain, or itcan refer to the albumin-binding protein of the first half-lifeextension domain in a masked cytokine comprising a first half-lifeextension domain and a second half-life extension domain, or it canrefer to the albumin-binding protein of the second half-life extensiondomain in a masked cytokine comprising a first half-life extensiondomain and a second half-life extension domain, or it can refer to thealbumin-binding protein of the first half-life extension domain and thealbumin-binding protein of the second half-life extension domain in amasked cytokine comprising a first half-life extension domain and asecond half-life extension domain.

In some embodiments, the albumin-binding protein comprises analbumin-binding domain (ABD) of Streptococcal protein G (SPG). See,e.g., Nygren et al. J. Mol. Recogn. (1988) 1(2): 69-74. In someembodiments, the albumin-binding protein comprises an ABD of SPG strainG148. In some embodiments, the albumin-binding protein comprises theC-terminal albumin-binding domain 3 (ABD3) of SPG strain G148. See,e.g., Nilvebrant and Hober (2013), Comput. Struct. Biotechol. J., 6:e201303009. In some embodiments, the albumin-binding protein comprisesthe amino acid sequence of SEQ ID NO: 172. In some embodiments, thealbumin-binding protein comprises an amino acid sequence having about orat least about 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%,96%, 97%, 98%, or 99% sequence identity to the amino acid sequence ofSEQ ID NO: 172.

In some embodiments, the albumin-binding protein comprises a natural orsynthetic peptide. In some embodiments, the albumin-binding proteincomprises the amino acid sequence of SEQ ID NO: 173 or 174. In someembodiments, the albumin-binding protein comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of SEQ ID NO: 173 or 174.

In some embodiments, an albumin-binding domain comprises an amino acidsequence produced by introducing one or more modifications to the aminoacid sequence of the albumin-binding domain, such as by introducing oneor more amino acid substitutions, additions, or deletions to the aminoacid sequence of any one of SEQ ID NOs: 172-174.

In some embodiments, the albumin-binding protein is a single-domainantibody or fragment thereof, such as a Nanobody, that binds to orotherwise associates with albumin. See, e.g., WO 2004041865A2 andUS20070269422A1, the contents of which are herein incorporated byreference. In some embodiments, the single-domain antibody or fragmentthereof comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 252-259. In some embodiments, thesingle-domain antibody or fragment thereof comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to anamino acid sequence selected from the group consisting of SEQ ID NOs:252-259.

In some embodiments, the albumin-binding protein is linked to a maskingmoiety. In some embodiments, a masking moiety is linked to theamino-terminus or the carboxy-terminus of the albumin-binding protein.In some embodiments, the albumin-binding protein is linked to a maskingmoiety via a linker. In some embodiments, a linker is linked to theamino-terminus or the carboxy-terminus of the albumin-binding protein.In some embodiments, an N-terminal spacer domain or a C-terminal spacerdomain of the linker is linked to the amino-terminus or thecarboxy-terminus of the albumin-binding domain. In some embodiments, acleavable peptide of the linker is linked to the amino-terminus or thecarboxy-terminus of the albumin-binding domain. In some embodiments, thealbumin-binding protein is linked to a cytokine or functional fragmentthereof. In some embodiments, a cytokine or functional fragment thereofis linked to the amino-terminus or the carboxy-terminus of thealbumin-binding protein. In some embodiments, the albumin-bindingprotein is linked to a cytokine or functional fragment thereof via alinker. In some embodiments, a linker is linked to the amino-terminus orthe carboxy-terminus of the albumin-binding protein.

Another example of a binding protein is an IgG-binding protein.IgG-binding proteins have been reported. For an overview of IgG-bindingproteins, including specific IgG-binding proteins and theirapplications, see, e.g., Choe et al. (2016) Materials 9(12): 994, thecontents of which are herein incorporated by reference.

In some embodiments of the masked cytokine, the half-life extensiondomain comprises an IgG-binding protein. In some embodiments, the maskedcytokine comprises more than one IgG-binding protein, each of which canbe any of the IgG-binding proteins described herein. In someembodiments, the masked cytokine comprises a first half-life extensiondomain and a second half-life extension domain, each of which comprisesan IgG-binding protein. It is understood that reference to “anIgG-binding protein” or “the IgG-binding protein” can refer to theIgG-binding protein of the half-life extension domain in a maskedcytokine comprising a single half-life extension domain, or it can referto the IgG-binding protein of the first half-life extension domain in amasked cytokine comprising a first half-life extension domain and asecond half-life extension domain, or it can refer to the IgG-bindingprotein of the second half-life extension domain in a masked cytokinecomprising a first half-life extension domain and a second half-lifeextension domain, or it can refer to the IgG-binding protein of thefirst half-life extension domain and the IgG-binding protein of thesecond half-life extension domain in a masked cytokine comprising afirst half-life extension domain and a second half-life extensiondomain.

In some embodiments, the half-life extension domain comprises anIgG-binding protein. The IgG-binding protein can be any IgG-bindingprotein. The IgG-binding protein can be any IgG-binding proteindescribed, e.g., in Choe et al. (2016) Materials 9(12): 994;US20140046037A1. For instance, a variety of bacterial proteins have beenshown to bind to mammalian IgGs, including Protein A, G, L, and Z, andfusion proteins of Protein LG and LA. See, e.g., Choe et al. (2016)Materials 9(12): 994. In some embodiments, the IgG-binding protein is aStaphylococcal protein A (SpA) protein from the bacterium Staphylococcusaureus, or fragment or variant thereof. In some embodiments, theIgG-binding domain is an IgG-binding domain of SpA, or a fragment orvariant thereof. In some embodiments, the IgG-binding domain is one ormore of the SpA IgG-binding domain E, D, A, B, C, and Z, or fragments orvariants thereof.

In some embodiments, the IgG-binding domain comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 175-186. Insome embodiments, the IgG-binding protein comprises an amino acidsequence having about or at least about 85%, 86%, 87%, 88%, 89%, 90%,91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to theamino acid sequence of any one of SEQ ID NOs: 175-186.

In some embodiments, an IgG-binding domain comprises an amino acidsequence produced by introducing one or more modifications to the aminoacid sequence of the IgG-binding domain, such as by introducing one ormore amino acid substitutions, additions, or deletions to the amino acidsequence of any one of SEQ ID NOs: 175-186.

In some embodiments, the IgG-binding protein is linked to a maskingmoiety. In some embodiments, a masking moiety is linked to theamino-terminus or the carboxy-terminus of the IgG-binding protein. Insome embodiments, the IgG-binding protein is linked to a masking moietyvia a linker. In some embodiments, a linker is linked to theamino-terminus or the carboxy-terminus of the IgG-binding protein. Insome embodiments, an N-terminal spacer domain or a C-terminal spacerdomain of the linker is linked to the amino-terminus or thecarboxy-terminus of the IgG-binding domain. In some embodiments, acleavable peptide of the linker is linked to the amino-terminus or thecarboxy-terminus of the IgG-binding domain. In some embodiments, theIgG-binding protein is linked to a cytokine or functional fragmentthereof. In some embodiments, a cytokine or functional fragment thereofis linked to the amino-terminus or the carboxy-terminus of theIgG-binding protein. In some embodiments, the IgG-binding protein islinked to a cytokine or functional fragment thereof via a linker. Insome embodiments, a linker is linked to the amino-terminus or thecarboxy-terminus of the IgG-binding protein.

4. Antibody Derivatives

The masked cytokines described herein may alternatively be linked tovarious antibody derivatives including, but not limited to, an scFv, anscFc, a dual-variable domain (DVD), and antibody derivatives based onthe CrossMab approach. See, e.g., Klein et al. (2012), MAbs, 4(6):653-663; U520070071675A1. The antibody derivatives include antibodyderivatives engineered as bispecific antibodies or fragments thereof. Assuch, in some embodiments, a half-life extension domain can comprise anyantibody derivative, variant, or fusion product thereof including, butnot limited to an scFv, an scFc, a dual-variable domain (DVD), antibodyderivatives based on the CrossMab approach, and bispecific antibodies orfragments thereof.

5. Polyamino Acid Sequences

An additional strategy for extending the half-life of masked cytokinesin serum is by linking the masked cytokine to a polyamino acid sequence.As such, in some embodiments, the half-life extension domain comprises apolyamino acid sequence. The polyamino acid sequence can be anypolyamino acid sequence capable of extending the half-life of the maskedcytokine in serum when it is linked to the masked cytokine. Examples ofpolyamino acid sequences include PAS polypeptides and XTEN polypeptides.

In some embodiments, the polyamino acid sequence is a polypeptide chaincomprising the small amino acid residues proline, alanine, and,optionally, serine (PAS polypeptide). PAS sequences are hydrophilic anduncharged polymers that have biophysical properties similar topolyethylene glycol (PEG), which is commonly linked to therapeuticproteins as a strategy for extending the therapeutic protein's half-lifein vivo. See, e.g., Schlapschy et al. (2013) Protein Eng. Des. Sel.,26(8): 489-501; WO2008155134A1; WO2011144756A1; WO2016130451A1, thecontents of which are herein incorporated by reference. Attachment of aPAS polypeptide to a therapeutic protein has been observed to increasestability in vivo and/or in vitro compared to the therapeutic protein inits native state without the PAS polypeptide attached. In someembodiments, the PAS polypeptide assumes a random coil conformation. Insome embodiments, the PAS polypeptide forms a random coil conformationdomain.

In some embodiments, the half-life extension domain comprises a PASpolypeptide that comprises the amino acid residues proline and alanine.In some embodiments, the half-life extension domain comprises a PASpolypeptide that comprises the amino acid residues proline, alanine, andserine. In some embodiments, the PAS polypeptide comprises at least 25amino acid residues, at least 50 amino acid residues, at least 100 aminoacid residues, at least 150 amino acid residues, at least 200 amino acidresidues, at least 250 amino acid residues, at least 300 amino acidresidues, at least 400 amino acid residues, at least 500 amino acidresidues, at least 600 amino acid residues, at least 700 amino acidresidues, at least 800 amino acid residues, at least 900 amino acidresidues, at least 1000 amino acid residues, at least 1100 amino acidresidues, at least 1200 amino acid residues, at least 1300 amino acidresidues, at least 1500 amino acid residues, at least 2000 amino acidresidues, at least 2500 amino acid residues, or at least 3000 amino acidresidues. In some embodiments, the PAS polypeptide comprises at least 25amino acid residues, at least 50 amino acid residues, at least 100 aminoacid residues, at least 150 amino acid residues, at least 200 amino acidresidues, at least 250 amino acid residues, at least 300 amino acidresidues, at least 400 amino acid residues, at least 500 amino acidresidues, at least 600 amino acid residues, at least 700 amino acidresidues, at least 800 amino acid residues, at least 900 amino acidresidues, at least 1000 amino acid residues, at least 1100 amino acidresidues, at least 1200 amino acid residues, at least 1300 amino acidresidues, at least 1500 amino acid residues, at least 2000 amino acidresidues, at least 2500 amino acid residues, or at least 3000 amino acidresidues, wherein each amino acid residue is either a proline or analanine. In some embodiments, the PAS polypeptide comprises at least 25amino acid residues, at least 50 amino acid residues, at least 100 aminoacid residues, at least 150 amino acid residues, at least 200 amino acidresidues, at least 250 amino acid residues, at least 300 amino acidresidues, at least 400 amino acid residues, at least 500 amino acidresidues, at least 600 amino acid residues, at least 700 amino acidresidues, at least 800 amino acid residues, at least 900 amino acidresidues, at least 1000 amino acid residues, at least 1100 amino acidresidues, at least 1200 amino acid residues, at least 1300 amino acidresidues, at least 1500 amino acid residues, at least 2000 amino acidresidues, at least 2500 amino acid residues, or at least 3000 amino acidresidues, wherein each amino acid residue is an amino acid selected fromthe group consisting of a proline, an alanine, and a serine.

In some embodiments, the polyamino acid sequence is an extendedrecombinant polypeptide (XTEN polypeptide). XTEN polypeptides arepolypeptides with non-naturally occurring, substantially non-repetitivesequences having a low degree or no secondary or tertiary structureunder physiologic conditions. XTEN polypeptides typically have fromabout 36 to about 3000 amino acid residues, of which the majority or theentirety are small hydrophilic amino acids (e.g., arginine, lysine,threonine, alanine, asparagine, glutamine, aspartate, glutamate, serine,and glycine). The physiochemical properties, as well as the unstructuredcharacteristic, of XTEN polypeptides is result, in part, from theoverall amino acid composition that is disproportionately limited to 4-6types of hydrophilic amino acids, the linking of the amino acids in anon-repetitive design, and the length of the XTEN polypeptide. Theattachment of an XTEN polypeptide to a therapeutic protein has beenobserved to improve solubility and stability, and to enhance thehalf-life of the therapeutic protein. See, e.g., Podust et al. (2016) J.Controlled Release, 240: 52-66; WO2013130683A2, the contents of whichare herein incorporated by reference.

In some embodiments, the half-life extension domain comprises an XTENpolypeptide that comprises an amino acid sequence that is made up offour, five, or six types of amino acid residues selected from the groupconsisting of glycine (G), alanine (A), serine (S), threonine (T),glutamate (E) and proline (P).

In some embodiments, the XTEN polypeptide comprises an amino acidsequence of about 25 to about 500 amino acid residues, about 200 toabout 1000 amino acid residues, about 500 to about 1500 amino acidresidues, about 1000 to about 2000 amino acid residues, or about 1500 toabout 3000 amino acid residues. In some embodiments, at least about 70%,75%, 80%, or 85% of the amino acid sequence consists of non-overlappingsequence motifs. In some embodiments, each of the motifs has 5 to 100amino acid residues, 5 to 50 amino acids residues, or 9 to 36 amino acidresidues, and wherein at least 90%, at least 91%, at least 92%, at least93%, at least 94%, at least 95%, at least 96%, at least 97%, at least98%, at least 99%, or 100% of each of the motifs consists of four, five,or six types of amino acid residues selected from the group consistingof glycine (G), alanine (A), serine (S), threonine (T), glutamate (E)and proline (P), In some embodiments, the content of any one amino acidtype in the full-length XTEN polypeptide does not exceed about 40%,about 35%, about 30%, about 25%, about 15%, about 10%, or about 8%.

In some embodiments, the XTEN polypeptide comprises an amino acidsequence of about 25 to about 500 amino acid residues, about 200 toabout 1000 amino acid residues, about 500 to about 1500 amino acidresidues, about 1000 to about 2000 amino acid residues, or about 1500 toabout 3000 amino acid residues, wherein at least about 80% of the aminoacid sequence consists of non-overlapping sequence motifs where each ofthe motifs has 9 to 36 amino acid residues and wherein at least 90%, atleast 91%, at least 92%, at least 93%, at least 94%, at least 95%, atleast 96%, at least 97%, at least 98%, at least 99%, or 100% of each ofthe motifs consists of four, five, or six types of amino acid residuesselected from the group consisting of glycine (G), alanine (A), serine(S), threonine (T), glutamate (E) and proline (P), and wherein thecontent of any one amino acid type in the full-length XTEN polypeptidedoes not exceed about 40%, about 35%, about 30%, about 25%, about 15%,about 10%, or about 8%.

6. PEGylation and Glycosylation

Additional strategies for extending the half-life of the maskedcytokines provided herein include PEGylation and the engineering ofadditional glycosylation sites. Each of these strategies is discussed infurther detail below.

“PEGylation” refers to a process of covalent or non-covalent attachmentor amalgamation of polyethylene glycol (PEG) polymer chains to moleculesand macrostructures, such as a drug, therapeutic protein, polypeptide,antibody, antibody fragment, antibody derivative, or to any of themasked cytokines or components thereof provided herein (e.g., thehalf-life extension domain of a masked cytokine and/or the cytokine orfunctional fragment thereof of the masked cytokine). The benefits ofPEGylation include, for example, (1) markedly improved circulatinghalf-lives in vivo due to either evasion of renal clearance as a resultof the polymer increasing the apparent size of the molecule to above theglomerular filtration limit, and/or through evasion of cellularclearance mechanisms, (2) reduced antigenicity and immunogenicity of themolecule to which PEG is attached, (3) improved pharmacokinetics, (4)improved solubility, (5) improved formulation and dosing options, (6)improved bioavailability via reduced losses at subcutaneous injectionsites, (7) improved thermal and mechanical stability of the PEGylatedmolecule.

Methods for the pegylation of various molecules and macrostructures arewell known in the art. See, e.g., US20140256636A1; Fee and Damodaran(2010) European Pharmaceutical Review, 15(1): 18-26; Chapman et al.(1999) Nature Biotechnol., 17: 780-783; Yang et al. (2003), ProteinEng., 16(10): 761-770; Chapman, Adv. Drug. Deliv. Rev. (2002), 54(4):531-545, the contents of which are herein incorporated by reference.

In some embodiments, the masked cytokine of any of the embodimentsherein is PEGylated. For instance, in some embodiments, this isaccomplished by functionalizing PEG with group-specific reagents so thatthe conjugation of PEG to the protein (e.g., a half-life extensiondomain, or a cytokine or functional fragment thereof) can be targeted tospecific side chain groups of the protein, such as amino, carboxyl,sulfhydryl, or guanidine groups. In some embodiments, cysteine (C)residues are introduced by amino acid substitution into the protein(e.g., a half-life extension domain, or a cytokine or functionalfragment thereof) in a site-specific manner. The thiol groups of thenewly introduced cysteine residues can then be targeted for PEGylationusing malemide chemistry-based PEG reagents. The replacement of serine(S) or threonine (T) with cysteine has an advantage in that the netcharge of the modified protein is not altered as a result of thePEGylation. As such, in some embodiments, a component of the maskedcytokine, such as any of the cytokines or functional fragments thereofand/or any of the half-life extension domains, can be modified, orfurther modified, by introducing cysteine residues for PEGylation.

“Glycosylation” refers to the addition of saccharides or glycosyl groupsto a polypeptide. Glycosylation of polypeptides is typically eitherN-linked or O-linked. N-linked refers to the attachment of acarbohydrate moiety to the side chain of an asparagine residue. Thetripeptide sequences asparagine-X-serine (N—X—S) andasparagine-X-threonine (N-X-T), where X is any amino acid except proline(P), are the recognition sequences for enzymatic attachment of thecarbohydrate moiety to the asparagine side chain. Thus, the presence ofeither of these tripeptide sequences in a polypeptide creates apotential glycosylation site. O-linked glycosylation refers to theattachment of one of the sugars (e.g., N-aceylgalactosamine, galactose,or xylose) to a hydroxyamino acid, most commonly serine or threonine,although 5-hydroxyproline or 5-hydroxylysine may also be used.

Naturally-occurring glycosylation has been shown to increase themolecular stability of proteins. See, e.g., Sola et al. (2007), Cell.Mol. Life Sci., 64(16): 2133-2152. It has also been shown that theengineering of additional glycosylation sites can stabilize a variety ofprotein therapeutics against most major physiochemical instabilities.See, e.g., Sola and Griebenow (2009), J. Pharm. Sci., 98(4): 1223-1245.Among the pharmaceutically relevant protein instabilities that have beenshown to be improved by glycosylation are, for example, oxidation;cross-linking; pH-, chemical-, thermal-, and freezing-induceddenaturation/unfolding; precipitation; kinetic activation; andaggregation. Id.

Addition of glycosylation sites to the masked cytokine is convenientlyaccomplished by altering the amino acid sequence such that one or moreof the above-described tripeptide sequences (for N-linked glycosylationsites) is created in the amino acid sequence of the masked cytokine(e.g., in the amino acid sequence of the half-life extension domainand/or the cytokine or functional fragment thereof). The alteration mayalso be made by the addition to, or substitution of, one or more serineor threonine residues in the amino acid sequence of the masked cytokine(e.g., in the amino acid sequence of the half-life extension domainand/or the cytokine or functional fragment thereof) (for O-linkedglycosylation sites).

In some embodiments, the masked cytokine of any of the embodimentsherein is modified, or is further modified, by altering the amino acidsequence of the masked cytokine (e.g., the amino acid sequence of thehalf-life extension domain and/or the cytokine or functional fragmentthereof) such that one or more additional N—X—S and/or N-X-T tripeptidesequence(s) is/are introduced into the amino acid sequence of the maskedcytokine or component thereof (for the addition of one or more N-linkedglycosylation sites). In some embodiments, the masked cytokine of any ofthe embodiments herein is modified, or is further modified, by alteringthe amino acid sequence of the masked cytokine or component thereof(e.g., the amino acid sequence of the half-life extension domain and/orthe cytokine or functional fragment thereof) such that one or moreadditional serine or threonine residues is/are introduced into the aminoacid sequence of the masked cytokine or component thereof (for theaddition of one or more O-linked glycosylation sites). In someembodiments, the alteration of the amino acid sequence for the additionof one or more N-linked glycosylation sites and/or for the addition ofone or more O-linked glycosylation sites is accomplished by the additionof one or more amino acids to the amino acid sequence of the maskedcytokine or component thereof. In some embodiments, the alteration ofthe amino acid sequence for the addition of one or more N-linkedglycosylation sites and/or for the addition of one or more O-linkedglycosylation sites is accomplished by the substitution of one or moreamino acids in the amino acid sequence of the masked cytokine orcomponent thereof. In some embodiments, the alteration of the amino acidsequence for the addition of one or more N-linked glycosylation sitesand/or for the addition of one or more O-linked glycosylation sites isaccomplished by the addition of one or more amino acids to the aminoacid sequence and by the substitution of one or more amino acids in theamino acid sequence of the masked cytokine or component thereof.

7. Heterodimerization Modifications

The half-life extension domains described herein may include one or moremodifications that promote heterodimerization of two different half-lifeextension domains. In some embodiments comprising a first half-lifeextension domain and a second half-life extension domain, it isdesirable to promote heterodimerization of the first and secondhalf-life extension domains such that production of the masked cytokinein its correct heterodimeric form is produced efficiently. As such, oneor more amino acid modifications can be made to the first half-lifeextension domain and one or more amino acid modifications can be made tothe second half-life extension domain using any strategy available inthe art, including any strategy as described in Klein et al. (2012),MAbs, 4(6): 653-663. Exemplary strategies and modifications aredescribed in detail below.

a. Knobs-into-Holes Approach

One strategy for promoting heterodimerization of two different half-lifeextension domains is an approach termed the “knobs-into-holes.”

In some embodiments, the masked cytokine comprises a first half-lifeextension domain and a second half-life extension domain, each of whichcomprises a CH3 domain. In some embodiments, the half-life extensiondomain comprising a CH3 domain is a heavy chain polypeptide or afragment thereof (e.g., an Fc domain or fragment thereof). The CH3domains of the two half-life extension domains can be altered by the“knobs-into-holes” technology, which is described in detail with severalexamples in, e.g., WO 1996/027011; Ridgway, J. B. et al., Protein Eng.(1996) 9(7): 617-621; Merchant, A. M., et al., Nat. Biotechnol. (1998)16(7): 677-681. See also Klein et al. (2012), MAbs, 4(6): 653-663. Usingthe knob-into-holes method, the interaction surfaces of the two CH3domains are altered to increase the heterodimerization of the twohalf-life extension domains containing the two altered CH3 domains. Thisoccurs by introducing a bulky residue into the CH3 domain of one of thehalf-life extension domains, which acts as the “knob.” Then, in order toaccommodate the bulky residue, a “hole” is formed in the other half-lifeextension domain that can accommodate the knob. Either of the alteredCH3 domains can be the “knob” while the other can be the “hole.” Theintroduction of a disulfide bridge further stabilizes the heterodimers(Merchant, A. M., et al., Nat. Biotechnol. (1998) 16(7); Atwell, S., etal., J. Mol. Biol. (1997) 270(1): 26-35) as well as increases yield.

It has been reported that heterodimerization yields above 97% can beachieved by introducing the S354C and T366W mutations in a heavy chainto create the “knob” and by introducing the Y349C, T366S, L368A, andY407V mutations in a heavy chain to create the “hole” (numbering of theresidues according to the Kabat EU numbering system). Carter et al.(2001), J. Immunol. Methods, 248: 7-15; Klein et al. (2012), MAbs, 4(6):653-663.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises a heavy chain polypeptide or portion thereof (e.g., an Fcdomain or fragment thereof) that comprises one or more amino acidmutations that create a “knob,” and the second half-life extensiondomain comprises a heavy chain polypeptide or portion thereof (e.g., anFc domain or fragment thereof) that comprises one or more amino acidmutations that create a “hole.” In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises a heavy chain polypeptide orportion thereof (e.g., an Fc domain or fragment thereof) that comprisesone or more amino acid mutations that create a “hole,” and the secondhalf-life extension domain comprises a heavy chain polypeptide orportion thereof (e.g., an Fc domain or fragment thereof) that comprisesone or more amino acid mutations that create a “knob.” Methods forintroducing a hole or knob in a heavy chain polypeptide or portionthereof (e.g., an Fc domain or fragment thereof) is known in the art,e.g., in WO 1996/027011; Ridgway, J. B. et al., Protein Eng. (1996)9(7): 617-621; Merchant, A. M., et al., Nat. Biotechnol. (1998) 16(7):677-681; Klein et al. (2012), MAbs, 4(6): 653-663.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises a heavy chain polypeptide or portion thereof (e.g., an Fcdomain or fragment thereof) that comprises the amino acid mutationsS354C and T366W (numbered according to the Kabat EU numbering system),and the second half-life extension domain comprises a heavy chainpolypeptide or portion thereof (e.g., an Fc domain or fragment thereof)that comprises the amino acid mutations Y349C, T366S, L368A, and Y407V(numbered according to the Kabat EU numbering system). In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises a heavy chain polypeptide or portion thereof (e.g., an Fcdomain or fragment thereof) that comprises the amino acid mutationsY349C, T366S, L368A, and Y407V (numbered according to the Kabat EUnumbering system), and the second half-life extension domain comprises aheavy chain polypeptide or portion thereof (e.g., an Fc domain orfragment thereof) that comprises the amino acid mutations S354C andT366W (numbered according to the Kabat EU numbering system). In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 155, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 155. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 265, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 265. In someembodiments comprising a first half-life extension domain and a secondhalf-life extension domain, the first half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 155, and the second half-life extension domaincomprises an Fc domain or fragment thereof comprising the amino acidsequence of SEQ ID NO: 156. In some embodiments comprising a firsthalf-life extension domain and a second half-life extension domain, thefirst half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 156, and thesecond half-life extension domain comprises an Fc domain or fragmentthereof comprising the amino acid sequence of SEQ ID NO: 155.

Additional examples of substitutions that can be made to form knobs andholes include those described in US20140302037A1, the contents of whichare herein incorporated by reference. For example, in some embodiments,any of the following amino acid substitutions can be made to a firsthalf-life extension domain (“first domain”) and a paired secondhalf-life extension domain (“second domain”) that each contain an Fcdomain: (a) Y407T in the first domain and T366Y in the second domain;(b) Y407A in the first domain and T366W in the second domain; (c) F405Ain the first domain and T394W in the second domain; (d) F405W in thefirst domain and T394S in the second domain; (e) Y407T in the firstdomain and T366Y in the second domain; (f) T366Y and F405A in the firstdomain and T394W and Y407T in the second domain; (g) T366W and F405W inthe first domain and T394S and Y407A in the second domain; (h) F405W andY407A in the first domain and T366W and T394S in the second domain; or(i) T366W in the first domain and T366S, L368A, and Y407V in the seconddomain, numbered according to the Kabat EU numbering system.

In some embodiments, any of the following amino acid substitutions canbe made to a first half-life extension domain (“first domain”) and apaired second half-life extension domain (“second domain”) that eachcontain an Fc domain: (a) Y407T in the second domain and T366Y in thefirst domain; (b) Y407A in the second domain and T366W in the firstdomain; (c) F405A in the second domain and T394W in the first domain;(d) F405W in the second domain and T394S in the first domain; (e) Y407Tin the second domain and T366Y in the first domain; (f) T366Y and F405Ain the second domain and T394W and Y407T in the first domain; (g) T366Wand F405W in the second domain and T394S and Y407A in the first domain;(h) F405W and Y407A in the second domain and T366W and T394S in thefirst domain; or (i) T366W in the second domain and T366S, L368A, andY407V in the first domain, numbered according to the Kabat EU numberingsystem.

In embodiments comprising a first half-life extension domain and asecond half-life extension domain that each comprise an Fc domain, anyof the heterodimerizing alterations described herein can be used in theFc domains to promote heterodimerization of any of the masked cytokinesdescribed herein. For instance, any of the heterodimerizationalterations described herein, including combinations thereof, can beused to alter an amino acid sequence selected from the group consistingof SEQ ID NOs: 154-156, 158, 168, 169, 265, 616, 619, 622, 625, 721,772-774, 793, and 796.

b. Ionic/Electrostatic Interactions

Another strategy for promoting heterodimerization of two differenthalf-life extension domains is by stabilizing ionic interactions thatfavor heterodimerization through altering charged residues.

In some embodiments, the masked cytokine comprises a first half-lifeextension domain and a second half-life extension domain, each of whichcomprises a CH3 domain. In some embodiments, the half-life extensiondomain comprising a CH3 domain is a heavy chain polypeptide or afragment thereof (e.g., an Fc domain or fragment thereof). It has beenobserved that altering the charge polarities between two different Fcdomains can result in ionic interactions such that heterodimerization isfavored while homodimerization is suppressed. See, e.g., WO2006/106905A1; Gunasekaran et al. (2010) 285(25): 19637-19646. Forexample, it was observed that negatively charged E356 pairs of an Fcdomain pairs with positively charged K439 of another Fc domain,negatively charged E357, E357, and D399 of a first Fc domain pairs withpositively charged K439, K370, and K409, respectively, of a second Fcdomain. See WO 2006/106905A1; Gunasekaran et al. (2010) 285(25):19637-19646. As such, by introducing at least two of the mutations ofE356K, E357K, and D399K in a first Fc domain, and the mutations K370E,K409D, and K439E into a second Fc domain, efficient heterodimerizationcan be achieved while suppressing homodimer formation. Id. Efficientheterodimerization has been achieved by introducing K392D and K409Dmutations in a first Fc chain, and by introducing D399K and E356Kmutations in a second Fc chain. Gunasekaran et al. (2010) 285(25):19637-19646.

Additional examples of substitutions that can be made to charged pairsof amino acids include those described in US20140302037A1, the contentsof which are herein incorporated by reference. For instance, in someembodiments, any of the following amino acid substitutions can be madeto a first half-life extension domain (“first domain”) and a pairedsecond half-life extension domain (“second domain”) that each contain anFc domain: (a) K409E in the first domain and D399K in the second domain;(b) K409E in the first domain and D399R in the second domain; (c) K409Din the first domain and D399K in the second domain; (d) K409D in thefirst domain and D399R in the second domain; (e) K392E in the firstdomain and D399R in the second domain; (f) K392E in the first domain andD399K in the second domain; (g) K392D in the first domain and D399R inthe second domain; (h) K392D in the first domain and D399K in the seconddomain; (i) K409D and K360D in the first domain and D399K and E356K inthe second domain; (j) K409D and K370D in the first domain and D399K andE357K in the second domain; (k) K409D and K392D in the first domain andD399K, E356K, and E357K in the second domain; (1) K409D and K392D in thefirst domain and D399K in the second domain; (m) K409D and K392D in thefirst domain and D399K and E356K in the second domain; (n) K409D andK392D in the first domain and D399K and E357K in the second domain; (o)K409D and K370D in the first domain and D399K and D357K in the seconddomain; (p) D399K in the first domain and K409D and K360D in the seconddomain; and/or (q) K409D and K439D in the first domain and D399K andE356K in the second domain, numbered according to the Kabat EU numberingsystem.

In some embodiments, any of the following amino acid substitutions canbe made to a first half-life extension domain (“first domain”) and apaired second half-life extension domain (“second domain”) that eachcontain an Fc domain: (a) K409E in the second domain and D399K in thefirst domain; (b) K409E in the second domain and D399R in the firstdomain; (c) K409D in the second domain and D399K in the first domain;(d) K409D in the second domain and D399R in the first domain; (e) K392Ein the second domain and D399R in the first domain; (f) K392E in thesecond domain and D399K in the first domain; (g) K392D in the seconddomain and D399R in the first domain; (h) K392D in the second domain andD399K in the first domain; (i) K409D and K360D in the second domain andD399K and E356K in the first domain; (j) K409D and K370D in the seconddomain and D399K and E357K in the first domain; (k) K409D and K392D inthe second domain and D399K, E356K, and E357K in the first domain; (1)K409D and K392D in the second domain and D399K in the first domain; (m)K409D and K392D in the second domain and D399K and E356K in the firstdomain; (n) K409D and K392D in the second domain and D399K and E357K inthe first domain; (o) K409D and K370D in the second domain and D399K andD357K in the first domain; (p) D399K in the second domain and K409D andK360D in the first domain; and/or (q) K409D and K439D in the seconddomain and D399K and E356K in the first domain, numbered according tothe Kabat EU numbering system.

In some embodiments, any of the following amino acid substitutions canbe made to a first half-life extension domain (“first domain”) and apaired second half-life extension domain (“second domain”) that eachcontain an Fc domain: (a) K409D or K409E in the first domain and D399Kor D399R in the second domain; (b) K392D or K392E in the first domainand D399K or D399R in the second domain; (c) K439D or K439E in the firstdomain and E356K or E356R in the second domain; and/or (d) K370D orK370E in the first domain and E357K or E357R in the second domain,numbered according to the Kabat EU numbering system.

In some embodiments, any of the following amino acid substitutions canbe made to a first half-life extension domain (“first domain”) and apaired second half-life extension domain (“second domain”) that eachcontain an Fc domain: (a) K409D or K409E in the second domain and D399Kor D399R in the first domain; (b) K392D or K392E in the second domainand D399K or D399R in the first domain; (c) K439D or K439E in the seconddomain and E356K or E356R in the first domain; and/or (d) K370D or K370Ein the second domain and E357K or E357R in the first domain, numberedaccording to the Kabat EU numbering system.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain that each comprise an Fc domain, oneor more of the following substitutions may be further included in boththe first half-life extension domain and the second half-life extensiondomain to stabilize the heterodimers: R355D, R355E, K360D, and K360R.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises a heavy chain polypeptide or portion thereof (e.g., an Fcdomain or fragment thereof) that comprises one or more mutations thatpromote stabilizing ionic interactions with the second half-lifeextension domain while suppressing homodimerization, and the secondhalf-life extension domain comprises one or more mutations that promotestabilizing ionic interactions with the first half-life extension domainwhile suppressing homodimerization.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain, the first half-life extension domaincomprises a heavy chain polypeptide or portion thereof (e.g., an Fcdomain or fragment thereof) that comprises the amino acid mutationsK392D and K409D (numbered according to the Kabat EU numbering system),and the second half-life extension domain comprises a heavy chainpolypeptide or portion thereof (e.g., an Fc domain or fragment thereof)that comprises the amino acid mutations D399K and E356K (numberedaccording to the Kabat EU numbering system).

In embodiments comprising a first half-life extension domain and asecond half-life extension domain that each comprise an Fc domain, anyof the heterodimerizing alterations described herein can be used in theFc domains to promote heterodimerization of any of the masked cytokinesdescribed herein. For instance, any of the heterodimerizationalterations described herein, including combinations thereof, can beused to alter an amino acid sequence selected from the group consistingof SEQ ID NOs: 154-156, 158, 168, 169, 265, 616, 619, 622, 625, 721,772-774, 793, and 796.

c. Structural and Sequenced-Based Approaches

Another strategy for promoting heterodimerization of two differenthalf-life extension domains is by using structure- and sequence-basedapproaches to identify alterations that could promote heterodimerizationand/or suppress homodimerization.

Among the ways of identifying alterations that promoteheterodimerization is by performing structural calculations to determinethe energies of paired variant combinations for residues that interactacross the CH3-CH3 dimer interface, as was the approach taken in Mooreet al. (2011) 3(6): 546-557, the contents of which are hereinincorporated by reference. Moore et al. identified the pairs that werepredicted to have lower energy in the heterodimer form relative to thehomodimer form as a starting point for further analysis. It was observedthat a heterodimerization yield of 89% could be achieved by introducingS364H and F405A mutations in a first Fc domain and by introducing Y349Tand T394F mutations in a second Fc domain Id.

In some embodiments comprising a first half-life extension domain and asecond half-life extension domain that each comprise an Fc domain, thefirst half-life extension domain comprises amino acid mutations of S364Hand F405A, and the second half-life extension domain comprises aminoacid mutations of Y349T and T394F, numbered according to the Kabat EUnumbering system. In some embodiments comprising a first half-lifeextension domain and a second half-life extension domain that eachcomprise an Fc domain, the second half-life extension domain comprisesamino acid mutations of S364H and F405A, and the first half-lifeextension domain comprises amino acid mutations of Y349T and T394F,numbered according to the Kabat EU numbering system.

In embodiments comprising a first half-life extension domain and asecond half-life extension domain that each comprise an Fc domain, anyof the heterodimerizing alterations described herein can be used in theFc domains to promote heterodimerization of any of the masked cytokinesdescribed herein. For instance, any of the heterodimerizationalterations described herein, including combinations thereof, can beused to alter an amino acid sequence selected from the group consistingof SEQ ID NOs: 154-156, 158, 168, 169, 265, 616, 619, 622, 625, 721,772-774, 793, and 796.

E. Binding Assays

The strength, or affinity of immunological binding interactions, such asbetween a cytokine or functional fragment thereof and a binding partner(e.g., a target protein, such as a cytokine receptor) for which thecytokine or functional fragment thereof is specific, can be expressed interms of the dissociation constant (Kd) of the interaction, wherein asmaller Kd represents a greater affinity. For example, the binding ofthe IL-2 cytokine to the IL-2R cytokine receptor (e.g., the IL-2R or acomponent thereof, such as IL-2Rα, IL-2Rβ, IL-2Rγ, or combinationsthereof), can be expressed in terms of the Kd. In some embodiments, theimmunological binding interactions are between a masked cytokine (in thepresence or absence of a protease) and a target protein, such as acytokine receptor. In the context of IL-2 cytokine binding, the targetprotein could be the IL-2R (comprising the IL-2Rα, IL-2Rβ, and IL-2Rγchains), the IL-2Rα chain, the IL-2Rβ chain, or the IL-2Rα/P dimericcomplex Immunological binding properties of proteins can be quantifiedusing methods well known in the art. For example, one method comprisesmeasuring the rates of cytokine receptor (e.g., IL-2R)/cytokine (e.g.,IL-2) complex formation and dissociation, wherein those rates depend onthe concentrations of the complex partners, the affinity of theinteraction, and geometric parameters that equally influence the rate inboth directions. Both the “on rate constant” (Kon) and the “off rateconstant” (Koff) can be determined by calculation of the concentrationsand the actual rates of association and dissociation. The ratio ofKoff/Kon enables the cancelation of all parameters not related toaffinity, and is equal to the dissociation constant Kd. See Davies etal., Annual Rev Biochem. 59:439-473, (1990).

In some aspects, a masked cytokine described herein binds to a targetprotein with about the same or higher affinity upon cleavage with aprotease as compared to the parental cytokine that comprises a maskingmoiety but does not comprise a cleavable peptide. The target protein canbe any cytokine receptor. In some embodiments, the target protein isIL-2R (comprising the IL-2Rα, IL-2Rβ, and IL-2Rγ chains). In someembodiments, the target protein is IL-2Rα. In some embodiments, thetarget protein is IL-2Rβ. In some embodiments, the target protein is theIL-2Rα/P dimeric complex. In some embodiments, the target protein isIL-15R (comprising the IL-15Rα, IL-2Rβ, and IL-2Rγ chains), or is acomponent thereof, such as IL-15Rα, IL-2Rβ, or IL-2Rγ, or a combinationthereof.

In some embodiments, a masked cytokine provided herein that does notcomprise a cleavable peptide in the linker has a dissociation constant(Kd) of <1 μM, <150 nM, <100 nM, <50 nM, <10 nM, <1 nM, <0.1 nM, <0.01nM, or <0.001 nM (e.g. 10-8 M or less, e.g. from 10-8 M to 10-13 M,e.g., from 10-9 M to 10-13 M) with the target protein. In someembodiments, a masked cytokine provided herein that comprises acleavable peptide in the linker has a dissociation constant (Kd) of ≤1μM, ≤150 nM, ≤100 nM, ≤50 nM, ≤10 nM, ≤1 nM, ≤0.1 nM, ≤0.01 nM, or≤0.001 nM (e.g. 10-8 M or less, e.g. from 10-8 M to 10-13 M, e.g., from10-9 M to 10-13 M) with the target protein prior to cleavable with aprotease. In some embodiments, a masked cytokine provided herein thatcomprises a cleavable peptide in the linker has a dissociation constant(Kd) of ≤1 μM, ≤150 nM, ≤100 nM, ≤50 nM, ≤10 nM, ≤1 nM, ≤0.1 nM, ≤0.01nM, or ≤0.001 nM (e.g. 10-8 M or less, e.g. from 10-8 M to 10-13 M,e.g., from 10-9 M to 10-13 M) with the target protein upon cleavage witha protease. In some embodiments, the cytokine or functional fragmentthereof of a masked cytokine provided herein has a dissociation constant(Kd) of ≥500 μM, ≥250 μM, ≥200 μM, ≥150 μM, ≥100 μM, ≥50 μM, ≥10 μM, ≥1μM, ≥500 nM, ≥250 nM, ≥150 nM, ≥100 nM, ≥50 nM, ≥10 nM, ≥1 nM, ≥0.1 nM,≥0.01 nM, or ≥0.001 nM with the masking moiety of the masked cytokine.In some embodiments, the cytokine or functional fragment thereof of amasked cytokine provided herein has a dissociation constant (Kd) that isbetween about 200 μM and about 50 nM, such as about or at least about175 μM, about or at least about 150 μM, about or at least about 125 μM,about or at least about 100 μM, about or at least about 75 μM, about orat least about 50 μM, about or at least about 25 μM, about or at leastabout 5 μM, about or at least about 1 μM, about or at least about 750nM, about or at least about 500 nM, about or at least about 250 nM,about or at least about 150 nM, about or at least about 100 nM, about orat least about 75 nM, or about or at least about 50 nM. Assays forassessing binding affinity are well known in the art.

In some aspects, masked cytokines that exhibit a desired occlusion ratioare provided. The term “occlusion ratio” as used herein refers a ratioof (a) a maximum detected level of a parameter under a first set ofconditions to (b) a minimum detected value of that parameter under asecond set of conditions. For example, in the context of a masked IL-2polypeptide, the occlusion ratio refers to the ratio of (a) a maximumdetected level of target protein (e.g., IL-2R protein) binding to themasked IL-2 polypeptide in the presence of at least one protease capableof cleaving the cleavable peptide of the masked IL-2 polypeptide to (b)a minimum detected level of target protein (e.g., IL-2R protein) bindingto the masked IL-2 polypeptide in the absence of the protease. Thus, theocclusion ratio for a masked cytokine can be calculated by dividing theEC50 of the masked cytokine pre-cleavage by the EC50 of the maskedcytokine post-cleavage. The occlusion ratio of a masked cytokine canalso be calculated as the ratio of the dissociation constant of themasked cytokine before cleavage with a protease to the dissociationconstant of the masked cytokine after cleavage with a protease. In someembodiments, a greater occlusion ratio for the masked cytokine indicatesthat target protein bound by the masked cytokine occurs to a greaterextent (e.g., predominantly occurs) in the presence of a proteasecapable of cleaving the cleavable peptide of the masked cytokine than inthe absence of a protease.

In some embodiments, masked cytokines with an optimal occlusion ratioare provided herein. In some embodiments, an optimal occlusion ratio ofa masked cytokine indicates the masked cytokine has desirable propertiesuseful for the methods or compositions contemplated herein. In someembodiments, a masked cytokine provided herein exhibits an optimalocclusion ratio of about 2 to about 10,000, e.g., about 80 to about 100.In a further embodiment of any of the masked cytokine provided herein,the occlusion ratio is about 2 to about 7,500, about 2 to about 5,000,about 2 to about 2,500, about 2 to about 2,000, about 2 to about 1,000,about 2 to about 900, about 2 to about 800, about 2 to about 700, about2 to about 600, about 2 to about 500, about 2 to about 400, about 2 toabout 300, about 2 to about 200, about 2 to about 100, about 2 to about50, about 2 to about 25, about 2 to about 15, about 2 to about 10, about5 to about 10, about 5 to about 15, about 5 to about 20, about 10 toabout 100, about 20 to about 100, about 30 to about 100, about 40 toabout 100, about 50 to about 100, about 60 to about 100, about 70 toabout 100, about 80 to about 100, or about 100 to about 1,000. In someembodiments, a masked cytokine provided herein exhibits an optimalocclusion ratio of about 2 to about 1,000. Binding of a masked IL-2polypeptide to a target protein before cleavage and/or after cleavagewith a protease can be determined using techniques well known in the artsuch as by ELISA.

In some embodiments, a masking moiety described herein binds to acytokine or functional fragment thereof as described herein with loweraffinity than the affinity between the cytokine or functional fragmentthereof and a target protein (e.g., cytokine receptor). In certainembodiments, a masking moiety provided herein binds to a cytokine orfunctional fragment thereof as described herein with a dissociationconstant (Kd) of ≥500 μM, ≥250 μM, ≥200 μM, ≥150 μM, ≥100 μM, ≥50 μM,≥10 μM, ≥1 μM, ≥500 nM, ≥250 nM, ≥150 nM, ≥100 nM, ≥50 nM, ≥10 nM, ≥1nM, ≥0.1 nM, ≥0.01 nM, or ≥0.001 nM.

II. MASKED CYTOKINE PRODUCTION

The masked cytokines described herein are prepared using techniquesavailable in the art, exemplary methods of which are described.

A. Antibody Production

Some embodiments of the masked cytokine comprise an antibody or fragmentthereof. The following sections provide further detail on the productionof antibodies and antibody fragments, variants, and derivatives thereof,that may be used in some embodiments of the masked cytokine providedherein. In some embodiments, the masked cytokine is in the form of adimer produced by two copies of a masked cytokine that are associatedthrough disulfide bonds.

1. Antibody Fragments

The present invention encompasses, in some embodiments, antibodyfragments. The antibody fragments can be any antibody fragments, such asan Fc domain, a portion of the heavy chain, a portion of the lightchain, an Fab, an Fv, or an scFv, among other fragments. Antibodyfragments may be generated by traditional means, such as enzymaticdigestion, or by recombinant techniques. In certain circumstances, thereare advantages of linking antibody fragments, rather than wholeantibodies, to the masked cytokines described herein. For a review ofcertain antibody fragments, see Hudson et al. (2003) Nat. Med.9:129-134.

Various techniques have been developed for the production of antibodyfragments. Traditionally, these fragments were derived via proteolyticdigestion of intact antibodies (see, e.g., Morimoto et al., Journal ofBiochemical and Biophysical Methods 24:107-117 (1992); and Brennan etal., Science, 229:81 (1985)). However, these fragments can now beproduced directly by recombinant host cells. Fab, Fv and ScFv antibodyfragments can all be expressed in and secreted from E. coli and othercell types, such as HEK293 and CHO cells, thus allowing the facileproduction of large amounts of these fragments. Alternatively, Fab′-SHfragments can be directly recovered from culture media and chemicallycoupled to form F(ab′)2 fragments (Carter et al., Bio/Technology 10:163-167 (1992)). According to another approach, F(ab′)2 fragments can beisolated directly from recombinant host cell culture. Fab and F(ab′)2fragments with increased in vivo half-life comprising FcRN/salvagereceptor binding epitope residues are described in U.S. Pat. No.5,869,046. Other techniques for the production of antibody fragments foruse in the masked cytokines will be apparent to the skilledpractitioner. In certain embodiments, a masked cytokine comprises asingle chain Fv fragment (scFv). See WO 93/16185; U.S. Pat. Nos.5,571,894; and 5,587,458. scFv fusion proteins may be constructed toyield fusion of an effector protein at either the amino or the carboxyterminus of an scFv. See Antibody Engineering, ed. Borrebaeck, supra.Also, in some embodiments, bi-scFv comprising two scFvs linked via apolypeptide linker can be used with the masked cytokines.

The present invention includes, in some embodiments, a linear antibody(e.g., as described in U.S. Pat. No. 5,641,870) or a single chainimmunoglobulin comprising heavy and light chain sequences of theantibody linked via an appropriate linker. Such linear antibodies orimmunoglobulins may be monospecific or bispecific. Such a single chainimmunoglobulin can be dimerized to thereby maintain a structure andactivities similar to those of the antibody, which is originally atetramer. Also, in some embodiments, the antibody or fragment thereofmay be an antibody that has a single heavy chain variable region and hasno light chain sequence. Such an antibody is called a single domainantibody (sdAb) or a nanobody. These antibodies are also encompassed inthe meaning of the functional fragment of the antibody according to thepresent invention. Antibody fragments can be linked to the maskedcytokines described herein according to the guidance provided herein.

2. Humanized Antibodies

The invention encompasses, in some embodiments, humanized antibodies orantibody fragments thereof. In some embodiments, the humanizedantibodies can be any antibodies, including any antibody fragment.Various methods for humanizing non-human antibodies are known in theart. For example, a humanized antibody can have one or more amino acidresidues introduced into it from a source which is non-human. Thesenon-human amino acid residues are often referred to as “import”residues, which are typically taken from an “import” variable domain.Humanization can be essentially performed following the method of Winter(Jones et al. (1986) Nature 321:522-525; Riechmann et al. (1988) Nature332:323-327; Verhoeyen et al. (1988) Science 239:1534-1536), bysubstituting hypervariable region sequences for the correspondingsequences of a human antibody. Accordingly, such “humanized” antibodiesare chimeric antibodies (U.S. Pat. No. 4,816,567) wherein substantiallyless than an intact human variable domain has been substituted by thecorresponding sequence from a non-human species. In practice, humanizedantibodies are typically human antibodies in which some hypervariableregion residues and possibly some FR residues are substituted byresidues from analogous sites in rodent antibodies. Humanized antibodiescan be linked to the masked cytokines described herein according to theguidance provided herein.

3. Human Antibodies

Human antibodies of some embodiments of the invention can be constructedby combining Fv clone variable domain sequence(s) selected fromhuman-derived phage display libraries with known human constant domainsequences(s). Alternatively, human monoclonal antibodies of someembodiments of the invention can be made by the hybridoma method, e.g.,by using mouse, rat, bovine (e.g., cow), or rabbit cells, for example,to produce the human monoclonal antibodies. In some embodiments, thehuman antibodies and human monoclonal antibodies can be antibodies thatbind to any antigen. In some embodiments, human monoclonal antibodies ofthe invention can be made by immunizing a non-human animal thatcomprises human immunoglobulin loci with the target antigen, andisolating the antibody from the immunized animal or from cells derivedfrom the immunized animal. Examples of suitable non-human animalsinclude a transgenic or transchromosomic animal, such as HuMAb Mouse®(Medarex, Inc.), KM Mouse®, “TC mice,” and Xenomouse™. See, e.g.,Lonberg, et al. (1994) Nature 368: 856-859; Fishwild, D. et al. (1996)Nature Biotechnology 14: 845-851; WO2002/43478; U.S. Pat. Nos.5,939,598; 6,075,181; 6,114,598; 6,150,584; 6,162,963; and Tomizuka etal. (2000) Proc. Natl. Acad. Sci. USA 97:722-727.

Human myeloma and murine-human heteromyeloma cell lines for theproduction of human monoclonal antibodies have been described, forexample, by Kozbor J. Immunol., 133: 3001 (1984); Brodeur et al.,Monoclonal Antibody Production Techniques and Applications, pp. 51-63(Marcel Dekker, Inc., New York, 1987); and Boerner et al., J. Immunol.,147: 86 (1991). Human antibodies can be linked to the masked cytokinesdescribed herein according to the guidance provided herein.

4. Bispecific Antibodies

Bispecific antibodies are monoclonal antibodies that have bindingspecificities for at least two different antigens. In certainembodiments, bispecific antibodies are human or humanized antibodies. Insome embodiments, one of the binding specificities is for a firstantigen and the other binding specificity is for a second antigen, whichmay be either two different epitopes on the same target protein, or twodifferent epitopes on two different target proteins. Bispecificantibodies may also be used to localize cytotoxic agents to cells whichexpress the first antigen and/or the second antigen. Bispecificantibodies may also be used to recruit cells, such as T cells or naturalkiller cells, to kill certain cells, e.g., cancer cells. Bispecificantibodies can be prepared as full-length antibodies or antibodyfragments (e.g. F(ab′)2 bispecific antibodies). Bispecific antibodiescan be linked to the masked cytokines described herein according to theguidance provided herein.

Methods for making bispecific antibodies are known in the art. SeeMilstein and Cuello, Nature, 305: 537 (1983), WO 93/08829 published May13, 1993, Traunecker et al., EMBO J., 10: 3655 (1991); Kontermann andBrinkmann, Drug Discovery Today, 20(7):838-847. For further details ofgenerating bispecific antibodies see, for example, Suresh et al.,Methods in Enzymology, 121:210 (1986). Bispecific antibodies includecross-linked or “heteroconjugate” antibodies. For example, one of theantibodies in the heteroconjugate can be coupled to avidin, the other tobiotin. Heteroconjugate antibodies may be made using any convenientcross-linking method. Suitable cross-linking agents are well known inthe art, and are disclosed in U.S. Pat. No. 4,676,980, along with anumber of cross-linking techniques.

5. Single-Domain Antibodies

In some embodiments, a single-domain antibody is linked to the maskedcytokine in accordance with the guidance provided herein. Thesingle-domain antibody can be any antibody. A single-domain antibody isa single polypeptide chain comprising all or a portion of the heavychain variable domain or all or a portion of the light chain variabledomain of an antibody. In certain embodiments, a single-domain antibodyis a human single-domain antibody (Domantis, Inc., Waltham, Mass.; see,e.g., U.S. Pat. No. 6,248,516 B1). In some embodiments, a single-domainantibody consists of all or a portion of the heavy chain variable domainof an antibody. In some embodiment, the single domain antibody is acamelid-derived antibody obtained by immunization of a camelid with thetarget antigen. In some embodiments, the single domain antibody is ashark-derived antibody obtained by immunization of a shark with thetarget antigen. In some embodiments, the single domain antibody is aNanobody (see, e.g., WO 2004041865A2 and US20070269422A1).

6. Antibody Variants

In some embodiments, amino acid sequence modification(s) of theantibodies or fragments thereof described herein are contemplated. Forexample, it may be desirable to improve the FcRn-binding affinity and/orpH-dependent FcRn-binding affinity of the antibody. It may also bedesirable to promote heterodimerization of antibody heavy chains byintroducing certain amino acid modifications. Methods for promotingheterodimerization of antibody chains, including certain modificationsthat can be made to facilitate heterodimerization, is described by Kleinet al. (2012), MAbs, 4(6): 653-663.

Amino acid sequence variants of the antibody may be prepared byintroducing appropriate changes into the nucleotide sequence encodingthe antibody, or by peptide synthesis. Such modifications include, forexample, deletions from, and/or insertions into and/or substitutions of,residues within the amino acid sequences of the antibody. Anycombination of deletion, insertion, and substitution can be made toarrive at the final construct, provided that the final constructpossesses the desired characteristics. The amino acid alterations may beintroduced in the subject antibody amino acid sequence at the time thatsequence is made.

A useful method for identification of certain residues or regions of theantibody that are preferred locations for mutagenesis is called “alaninescanning mutagenesis” as described by Cunningham and Wells (1989)Science, 244:1081-1085. Here, a residue or group of target residues areidentified (e.g., charged residues such as arg, asp, his, lys, and glu)and replaced by a neutral or negatively charged amino acid (e.g.,alanine or polyalanine) to affect the interaction of the amino acidswith antigen. Those amino acid locations demonstrating functionalsensitivity to the substitutions then are refined by introducing furtheror other variants at, or for, the sites of substitution. Thus, while thesite for introducing an amino acid sequence variation is predetermined,the nature of the mutation per se need not be predetermined. Forexample, to analyze the performance of a mutation at a given site, alascanning or random mutagenesis is conducted at the target codon orregion and the expressed immunoglobulins are screened for the desiredactivity.

Amino acid sequence insertions include amino- and/or carboxyl-terminalfusions ranging in length from one residue to polypeptides containing ahundred or more residues, as well as intrasequence insertions of singleor multiple amino acid residues. Examples of terminal insertions includean antibody with an N-terminal methionyl residue. Other insertionalvariants of the antibody molecule include the fusion to the N- orC-terminus of the antibody to an enzyme or a polypeptide which increasesthe serum half-life of the antibody.

In some embodiments, the masked cytokine is modified to eliminate,reduce, or otherwise hinder protease cleavage near the hinge region. The“hinge region” of an IgG is generally defined as including E216 andterminating at P230 of human IgG1 according to the EU index as in Kabat,but, functionally, the flexible portion of the chain may be consideredto include additional residues termed the upper and lower hinge regions,such as from E216 to G237 (Roux et al., 1998 J Immunol 161:4083) and thelower hinge has been referred to as residues 233 to 239 of the Fc regionwhere FcγR binding was generally attributed. Modifications to any of themasked cytokines described herein, can be performed, for example,according to the methods described in US 20150139984A1, which isincorporated herein by reference, as well as by incorporating any of themodifications described therein.

In some embodiments, FcRn mutations that improve pharmacokineticsinclude, but are not limited to, M428L, T250Q/M428L, M252Y/S254T/T256E,P257I/N434H, D376V/N434H, P257I/Q3111, N434A, N434W, M428L/N434S,V259I/V308F, M252Y/S254T/T256E, V259I/V308F/M428L, T307Q/N434A,T307Q/N434S, T307Q/E380A/N434A, V308P/N434A, N434H, V308P. In someembodiments, such mutations enhance antibody binding to FcRn at low pHbut do not change the antibody affinity at neutral pH.

In certain embodiments, an antibody or fragment thereof is altered toincrease or decrease the extent to which the antibody is glycosylated.Glycosylation of polypeptides is typically either N-linked or O-linked.N-linked refers to the attachment of a carbohydrate moiety to the sidechain of an asparagine residue. The tripeptide sequencesasparagine-X-serine and asparagine-X-threonine, where X is any aminoacid except proline, are the recognition sequences for enzymaticattachment of the carbohydrate moiety to the asparagine side chain.Thus, the presence of either of these tripeptide sequences in apolypeptide creates a potential glycosylation site. O-linkedglycosylation refers to the attachment of one of the sugarsN-aceylgalactosamine, galactose, or xylose to a hydroxyamino acid, mostcommonly serine or threonine, although 5-hydroxyproline or5-hydroxylysine may also be used.

Addition or deletion of glycosylation sites to the masked cytokine isconveniently accomplished by altering the amino acid sequence such thatone or more of the above-described tripeptide sequences (for N-linkedglycosylation sites) is created or removed. The alteration may also bemade by the addition, deletion, or substitution of one or more serine orthreonine residues to the sequence of the original antibody (forO-linked glycosylation sites).

Where the antibody or fragment thereof comprises an Fc region, thecarbohydrate attached thereto may be altered. For example, antibodieswith a mature carbohydrate structure that lacks fucose attached to an Fcregion of the antibody are described in US Pat Appl No US 2003/0157108(Presta, L.). See also US 2004/0093621 (Kyowa Hakko Kogyo Co., Ltd).Antibodies with a bisecting N-acetylglucosamine (GlcNAc) in thecarbohydrate attached to an Fc region of the antibody are referenced inWO 2003/011878, Jean-Mairet et al. and U.S. Pat. No. 6,602,684, Umana etal. Antibodies with at least one galactose residue in theoligosaccharide attached to an Fc region of the antibody are reported inWO 1997/30087, Patel et al. See, also, WO 1998/58964 (Raju, S.) and WO1999/22764 (Raju, S.) concerning antibodies with altered carbohydrateattached to the Fc region thereof. See also US 2005/0123546 (Umana etal.) on antigen-binding molecules with modified glycosylation.

In certain embodiments, a glycosylation variant comprises an Fc region,wherein a carbohydrate structure attached to the Fc region lacks fucoseor has reduced fucose. Such variants have improved ADCC function.Optionally, the Fc region further comprises one or more amino acidsubstitutions therein which further improve ADCC, for example,substitutions at positions 298, 333, and/or 334 of the Fc region (Eunumbering of residues). Examples of publications related to“defucosylated” or “fucose-deficient” antibodies include: US2003/0157108; WO 2000/61739; WO 2001/29246; US 2003/0115614; US2002/0164328; US 2004/0093621; US 2004/0132140; US 2004/0110704; US2004/0110282; US 2004/0109865; WO 2003/085119; WO 2003/084570; WO2005/035586; WO 2005/035778; WO2005/053742; Okazaki et al. J. Mol. Biol.336:1239-1249 (2004); Yamane-Ohnuki et al. Biotech. Bioeng. 87: 614(2004). Examples of cell lines producing defucosylated antibodiesinclude Lec13 CHO cells deficient in protein fucosylation (Ripka et al.Arch. Biochem. Biophys. 249:533-545 (1986); US Pat Appl No US2003/0157108 A1, Presta, L; and WO 2004/056312 A1, Adams et al.,especially at Example 11), and knockout cell lines, such asalpha-1,6-fucosyltransferase gene, FUT8, knockout CHO cells(Yamane-Ohnuki et al. Biotech. Bioeng. 87: 614 (2004)), and cellsoverexpressing β1,4-N-acetylglycosminyltransferase III (GnT-III) andGolgi μ-mannosidase II (ManII).

In any of the embodiments herein, the masked cytokine can be engineeredto improve antibody-dependent cell-mediated cytotoxicity (ADCC)activity. In some embodiments, the masked cytokine may be produced in acell line having a alpha1,6-fucosyltransferase (Fut8) knockout. In someembodiments, the host cells have been modified to have reduced intrinsicalpha1,6-fucosylation activity. Examples of methods for modifying thefucosylation pathways in mammalian host cells can be found in, e.g.,Yamane-Ohnuki and Satoh, MAbs, 1(3): 230-236 (2009), the contents ofwhich are incorporated herein by reference. Examples of methods andcompositions for partially or completely inactivating the expression ofthe FUT8 gene can be found in, e.g., US Pub. No. 20160194665A1;WO2006133148A2, the contents of which are incorporated herein byreference. In some embodiments, the masked cytokine is produced in theLec13 variant of CHO cells (see, e.g., Shields et al., J. Biol. Chem.,277(30):26733-40 (2002)) or the YB2/0 cell line having reduced FUT8activity (see, e.g., Shinkawa et al., J. Biol. Chem., 278(5): 3466-73(2003)). In some embodiments, small interfering RNA (siRNA) againstgenes relevant to alpha1,6-fucosylation can be introduced (see, e.g.,Mori et al., Biotechnol. Bioeng. 88(7): 901-908 (2004); Imai-Nishiya etal., BMC Biotechnol. 7: 84 (2007); Omasa et al., J. Biosci. Bioeng.,106(2): 168-173 (2008)). In some further embodiments, the maskedcytokine may be produced in a cell line overexpressingβ1,4-N-acetylglycosminyltransferase III (GnT-III). In furtherembodiments, the cell line additionally overexpresses Golgiμ-mannosidase II (ManII). In some of the embodiments herein, the maskedcytokine may comprise at least one amino acid substitution in the Fcregion that improves ADCC activity.

In some embodiments, the masked cytokine is altered to improve its serumhalf-life. To increase the serum half-life of the cytokine, one mayincorporate a FcRN/salvage receptor binding epitope into a linkedantibody (especially an antibody fragment) as described in U.S. Pat. No.5,739,277, for example. As used herein, the term “salvage receptorbinding epitope” refers to an epitope of the Fc region of an IgGmolecule (e.g., IgG1, IgG2, IgG3, or IgG4) that is responsible forincreasing the in vivo serum half-life of the IgG molecule (US2003/0190311, U.S. Pat. Nos. 6,821,505; 6,165,745; 5,624,821; 5,648,260;6,165,745; 5,834,597).

Another type of variant is an amino acid substitution variant. Thesevariants have at least one amino acid residue in the antibody moleculereplaced by a different residue. Sites of interest for substitutionalmutagenesis include the hypervariable regions, but FR alterations arealso contemplated. Conservative substitutions are shown in Table 3 underthe heading of “preferred substitutions.” If such substitutions resultin a desirable change in biological activity, then more substantialchanges, denominated “exemplary substitutions” in Table 3, or as furtherdescribed below in reference to amino acid classes, may be introducedand the products screened.

TABLE 3 Original Exemplary Preferred Residue Substitutions SubstitutionsAla (A) Val; Leu; Ile Val Arg (R) Lys; Gln; Asn Lys Asn (N) Gln; His;Asp, Lys; Arg Gln Asp (D) Glu; Asn Glu Cys (C) Ser; Ala Ser Gln (Q) Asn;Glu Asn Glu (E) Asp; Gln Asp Gly (G) Ala Ala His (H) Asn; Gln; Lys; ArgArg Ile (I) Leu; Val; Met; Ala; Phe; Norleucine Leu Leu (L) Norleucine;Ile; Val; Met; Ala; Phe Ile Lys (K) Arg; Gln; Asn Arg Met (M) Leu; Phe;Ile Leu Phe (F) Trp; Leu; Val; Ile; Ala; Tyr Tyr Pro (P) Ala Ala Ser (S)Thr Thr Thr (T) Val; Ser Ser Trp (W) Tyr; Phe Tyr Tyr (Y) Trp; Phe; Thr;Ser Phe Val (V) Ile; Leu; Met; Phe; Ala; Norleucine Leu

Substantial modifications in the biological properties of the antibodyare accomplished by selecting substitutions that differ significantly intheir effect on maintaining (a) the structure of the polypeptidebackbone in the area of the substitution, for example, as a sheet orhelical conformation, (b) the charge or hydrophobicity of the moleculeat the target site, or c) the bulk of the side chain Amino acids may begrouped according to similarities in the properties of their side chains(in A. L. Lehninger, in Biochemistry, second ed., pp. 73-75, WorthPublishers, New York (1975)):

-   -   (1) non-polar: Ala (A), Val (V), Leu (L), Ile (I), Pro (P), Phe        (F), Trp (W), Met (M)    -   (2) uncharged polar: Gly (G), Ser (S), Thr (T), Cys (C), Tyr        (Y), Asn (N), Gln (Q)    -   (3) acidic: Asp (D), Glu (E)    -   (4) basic: Lys (K), Arg (R), His (H)

Alternatively, naturally occurring residues may be divided into groupsbased on common side-chain properties:

-   -   (1) hydrophobic: Norleucine, Met, Ala, Val, Leu, Ile;    -   (2) neutral hydrophilic: Cys, Ser, Thr, Asn, Gln;    -   (3) acidic: Asp, Glu;    -   (4) basic: His, Lys, Arg;    -   (5) residues that influence chain orientation: Gly, Pro;    -   (6) aromatic: Trp, Tyr, Phe.

Non-conservative substitutions will entail exchanging a member of one ofthese classes for another class. Such substituted residues also may beintroduced into the conservative substitution sites or, into theremaining (non-conserved) sites.

Another type of substitutional variant involves the substitution of anaturally occurring amino acid residue for a non-naturally occurringamino acid residue. Non-naturally occurring amino acid residues can beincorporated, e.g., through tRNA recoding, or through any of the methodsas described, e.g., in WO 2016154675A1, which is incorporated herein byreference.

One type of substitutional variant involves substituting one or morehypervariable region residues of a parent antibody (e.g., a humanized orhuman antibody). Generally, the resulting variant(s) selected forfurther development will have modified (e.g., improved) biologicalproperties relative to the parent antibody from which they aregenerated. A convenient way for generating such substitutional variantsinvolves affinity maturation using phage display, yeast display, ormammalian display. Briefly, several hypervariable region sites (e.g.,6-7 sites) are mutated to generate all possible amino acid substitutionsat each site. The antibodies thus generated are displayed fromfilamentous phage particles as fusions to at least part of a phage coatprotein (e.g., the gene III product of M13) packaged within eachparticle. The phage-displayed variants are then screened for theirbiological activity (e.g., binding affinity). In order to identifycandidate hypervariable region sites for modification, scanningmutagenesis (e.g., alanine scanning) can be performed to identifyhypervariable region residues contributing significantly to antigenbinding. Alternatively, or additionally, it may be beneficial to analyzea crystal structure of the antigen-antibody complex to identify contactpoints between the antibody and antigen. Such contact residues andneighboring residues are candidates for substitution according totechniques known in the art, including those elaborated herein. Oncesuch variants are generated, the panel of variants is subjected toscreening using techniques known in the art, including those describedherein, and antibodies with superior properties in one or more relevantassays may be selected for further development.

Nucleic acid molecules encoding amino acid sequence variants of themasked cytokines are prepared by a variety of methods known in the art.These methods include, but are not limited to, isolation from a naturalsource (in the case of naturally occurring amino acid sequence variants)or preparation by oligonucleotide-mediated (or site-directed)mutagenesis, PCR mutagenesis, and cassette mutagenesis of an earlierprepared variant or a non-variant version of the antibody, for example.

It may be desirable to introduce one or more amino acid modifications inan Fc region of antibodies of the invention, thereby generating an Fcregion variant. The Fc region variant may comprise a human Fc regionsequence (e.g., a human IgG1, IgG2, IgG3 or IgG4 Fc region) comprisingan amino acid modification (e.g. a substitution) at one or more aminoacid positions including that of a hinge cysteine.

In some embodiments, a masked cytokine provided herein includes anantibody or fragment thereof having an IgG1, IgG2, IgG3, or IgG4 isotypewith enhanced effector function. In some embodiments, a masked cytokineprovided herein includes an antibody or fragment thereof having an IgG1isotype with enhanced effector function. In some embodiments, a maskedcytokine provided herein (e.g., a masked IL-2 polypeptide or functionalfragment thereof or a masked IL-15 polypeptide or functional fragmentthereof) has an IgG1 isotype with enhanced effector function. In someembodiments, the masked cytokine is afucosylated. In some embodiments,the masked cytokine has increased levels of mannose moieties. In someembodiments, the masked cytokine has increased levels of bisectingglycan moieties. In some embodiments, the IgG1 comprises amino acidmutations.

In some embodiments, a masked cytokine provided herein includes anantibody having an IgG1 isotype (e.g., a human IgG1 isotype). In someembodiments, the IgG1 comprises one or more amino acid substitutionsthat enhance effector function. In one embodiment, the IgG1 comprisesthe amino acid substitutions S298A, E333A, and K334A wherein the aminoacid residues are numbered according to the EU index as in Kabat. In oneembodiment, the IgG1 comprises the amino acid substitutions S239D andI332E wherein the amino acid residues are numbered according to the EUindex as in Kabat. In one embodiment, the IgG1 comprises the amino acidsubstitutions S239D, A330L, and I332E wherein the amino acid residuesare numbered according to the EU index as in Kabat. In one embodiment,the IgG1 comprises the amino acid substitutions P247I and A339D or A339Qwherein the amino acid residues are numbered according to the EU indexas in Kabat. In one embodiment, the IgG1 comprises the amino acidsubstitutions D280H, K290S with or without S298D or S298V wherein theamino acid residues are numbered according to the EU index as in Kabat.In one embodiment, the IgG1 comprises the amino acid substitutionsF243L, R292P, and Y300L wherein the amino acid residues are numberedaccording to the EU index as in Kabat. In one embodiment, the IgG1comprises the amino acid substitutions F243L, R292P, Y300L, and P396Lwherein the amino acid residues are numbered according to the EU indexas in Kabat. In one embodiment, the IgG1 comprises the amino acidsubstitutions F243L, R292P, Y300L, V305I, and P396L wherein the aminoacid residues are numbered according to the EU index as in Kabat. In oneembodiment, the IgG1 comprises the amino acid substitutions G236A,S239D, and I332E wherein the amino acid residues are numbered accordingto the EU index as in Kabat. In one embodiment, the IgG1 comprises theamino acid substitutions K326A and E333A wherein the amino acid residuesare numbered according to the EU index as in Kabat. In one embodiment,the IgG1 comprises the amino acid substitutions K326W and E333S whereinthe amino acid residues are numbered according to the EU index as inKabat. In one embodiment, the IgG1 comprises the amino acidsubstitutions K290E, S298G, T299A, with or without K326E wherein theamino acid residues are numbered according to the EU index as in Kabat.In one embodiment, the IgG1 comprises the amino acid substitutionsK290N, S298G, T299A, with or without K326E wherein the amino acidresidues are numbered according to the EU index as in Kabat. In oneembodiment, the IgG1 comprises the amino acid substitution K334V whereinthe amino acid residues are numbered according to the EU index as inKabat. In one embodiment, the IgG1 comprises the amino acidsubstitutions L235S, S239D, and K334V wherein the amino acid residuesare numbered according to the EU index as in Kabat. In one embodiment,the IgG1 comprises the amino acid substitutions K334V and Q331M, S239D,F243V, E294L, or S298T wherein the amino acid residues are numberedaccording to the EU index as in Kabat. In one embodiment, the IgG1comprises the amino acid substitutions E233L, Q311M, and K334V whereinthe amino acid residues are numbered according to the EU index as inKabat. In one embodiment, the IgG1 comprises the amino acidsubstitutions L234I, Q311M, and K334V wherein the amino acid residuesare numbered according to the EU index as in Kabat. In one embodiment,the IgG1 comprises the amino acid substitutions K334V and S298T, A330M,or A330F wherein the amino acid residues are numbered according to theEU index as in Kabat. In one embodiment, the IgG1 comprises the aminoacid substitutions K334V, Q311M, and either A330M or A330F wherein theamino acid residues are numbered according to the EU index as in Kabat.In one embodiment, the IgG1 comprises the amino acid substitutionsK334V, S298T, and either A330M or A330F wherein the amino acid residuesare numbered according to the EU index as in Kabat. In one embodiment,the IgG1 comprises the amino acid substitutions K334V, S239D, and eitherA330M or S298T wherein the amino acid residues are numbered according tothe EU index as in Kabat. In one embodiment, the IgG1 comprises theamino acid substitutions L234Y, Y296W, and K290Y, F243V, or E294Lwherein the amino acid residues are numbered according to the EU indexas in Kabat. In one embodiment, the IgG1 comprises the amino acidsubstitutions Y296W and either L234Y or K290Y wherein the amino acidresidues are numbered according to the EU index as in Kabat. In oneembodiment, the IgG1 comprises the amino acid substitutions S239D,A330S, and I332E wherein the amino acid residues are numbered accordingto the EU index as in Kabat.

In some embodiments, the IgG1 comprises one or more amino acidsubstitutions that decrease or inhibit effector function. In oneembodiment, the IgG1 comprises the amino acid substitution N297A, N297G,or N297Q wherein the amino acid residues are numbered according to theEU index as in Kabat. In one embodiment, the IgG1 comprises the aminoacid substitution L234A or L235A wherein the amino acid residues arenumbered according to the EU index as in Kabat. In one embodiment, theIgG1 comprises the amino acid substitutions C220S, C226S, C229S, andP238S wherein the amino acid residues are numbered according to the EUindex as in Kabat. In one embodiment, the IgG1 comprises the amino acidsubstitutions C226S, C229S, E233P, L234V, and L235A wherein the aminoacid residues are numbered according to the EU index as in Kabat. In oneembodiment, the IgG1 comprises the amino acid substitutions L234F,L235E, and P331S wherein the amino acid residues are numbered accordingto the EU index as in Kabat. In one embodiment, the IgG1 comprises theamino acid substitutions S267E and L328F wherein the amino acid residuesare numbered according to the EU index as in Kabat.

In accordance with this description and the teachings of the art, it iscontemplated that in some embodiments, an antibody or fragment thereofof the masked cytokine may comprise one or more alterations as comparedto the wild type counterpart antibody, e.g. in the Fc region. Forexample, it is thought that certain alterations can be made in the Fcregion that would result in altered (i.e., either improved ordiminished) Clq binding and/or Complement Dependent Cytotoxicity (CDC),e.g., as described in WO99/51642. See also Duncan & Winter Nature322:738-40 (1988); U.S. Pat. Nos. 5,648,260; 5,624,821; and WO94/29351concerning other examples of Fc region variants. WO00/42072 (Presta) andWO 2004/056312 (Lowman) describe antibody variants with improved ordiminished binding to FcRs. The content of these patent publications arespecifically incorporated herein by reference. See also Shields et al.J. Biol. Chem. 9(2): 6591-6604 (2001). Antibodies with increasedhalf-lives and improved binding to the neonatal Fc receptor (FcRn),which is responsible for the transfer of maternal IgGs to the fetus(Guyer et al., J. Immunol. 117:587 (1976) and Kim et al., J. Immunol.24:249 (1994)), are described in US2005/0014934A1 (Hinton et al.). Theseantibodies comprise an Fc region with one or more substitutions thereinwhich improve binding of the Fc region to FcRn. Polypeptide variantswith altered Fc region amino acid sequences and increased or decreasedClq binding capability are described in U.S. Pat. No. 6,194,551B1,WO99/51642. The contents of those patent publications are specificallyincorporated herein by reference. See, also, Idusogie et al. J. Immunol.164: 4178-4184 (2000).

B. Masked Cytokine-Drug Conjugates

The invention also provides masked cytokine-drug conjugates (MCDCs)comprising a masked cytokine provided herein, which can be any maskedcytokine disclosed herein, conjugated to one or more agents. In someembodiments, the one or more agents is a cytotoxic agent, such as achemotherapeutic agent or drug, growth inhibitory agent, toxin (e.g.,protein toxin, enzymatically active toxin of bacterial, fungal, plant,or animal origin, or fragments thereof), or radioactive isotopes. Insome embodiments, the one or more agents is an immune stimulant.

In some embodiments, the one or more drugs conjugated to the maskedcytokine includes, but is not limited to, a maytansinoid (see U.S. Pat.Nos. 5,208,020, 5,416,064 and European Patent EP 0 425 235 B1); anauristatin such as monomethylauristatin drug moieties DE and DF (MMAEand MMAF) (see U.S. Pat. Nos. 5,635,483 and 5,780,588, and 7,498,298); adolastatin; a calicheamicin or derivative thereof (see U.S. Pat. Nos.5,712,374, 5,714,586, 5,739,116, 5,767,285, 5,770,701, 5,770,710,5,773,001, and 5,877,296; Hinman et al., Cancer Res. 53:3336-3342(1993); and Lode et al., Cancer Res. 58:2925-2928 (1998)); ananthracycline such as daunomycin or doxorubicin (see Kratz et al.,Current Med. Chem. 13:477-523 (2006); Jeffrey et al., Bioorganic & Med.Chem. Letters 16:358-362 (2006); Torgov et al., Bioconj. Chem.16:717-721 (2005); Nagy et al., Proc. Natl. Acad. Sci. USA 97:829-834(2000); Dubowchik et al., Bioorg. & Med. Chem. Letters 12:1529-1532(2002); King et al., J. Med. Chem. 45:4336-4343 (2002); and U.S. Pat.No. 6,630,579); methotrexate; vindesine; a taxane such as docetaxel,paclitaxel, larotaxel, tesetaxel, and ortataxel; a trichothecene; andCC1065.

In another embodiment, the one or more drugs conjugated to the maskedcytokine includes, but is not limited to, an inhibitor of tubulinpolymerization (e.g., maytansinoids and auristatins), DNA damagingagents (e.g., pyrrolobenzodiazepine (PBD) dimers, calicheamicins,duocarmycins and indo-linobenzodiazepine dimers), and DNA synthesisinhibitors (e.g., exatecan derivative Dxd).

In another embodiment, a masked cytokine-drug conjugate comprises amasked cytokine as described herein conjugated to an enzymaticallyactive toxin or fragment thereof, including, but not limited to,diphtheria A chain, nonbinding active fragments of diphtheria toxin,exotoxin A chain (from Pseudomonas aeruginosa), ricin A chain, abrin Achain, modeccin A chain, alpha-sarcin, Aleurites fordii proteins,dianthin proteins, Phytolaca americana proteins (PAPI, PAPII, andPAP-S), Momordica charantia inhibitor, curcin, crotin, Sapaonariaofficinalis inhibitor, gelonin, mitogellin, restrictocin, phenomycin,enomycin, and the tricothecenes.

In another embodiment, a masked cytokine-drug conjugate comprises amasked cytokine as described herein conjugated to a radioactive atom toform a radioconjugate. A variety of radioactive isotopes are availablefor the production of radioconjugates. Examples include At211, 1131,1125, Y90, Re186, Re188, Sm153, Bi212, P32, Pb212 and radioactiveisotopes of Lu. When the radioconjugate is used for detection, it maycomprise a radioactive atom for scintigraphic studies, for example tc99mor 1123, or a spin label for nuclear magnetic resonance (NMR) imaging(also known as magnetic resonance imaging, mri), such as iodine-123again, iodine-131, indium-111, fluorine-19, carbon-13, nitrogen-15,oxygen-17, gadolinium, manganese or iron.

In some embodiments, a masked cytokine-drug conjugate comprises a maskedcytokine as described herein conjugated to one or more immunestimulants. In some embodiments, the immune stimulant is a stimulator ofinterferon genes (STING) agonist or a toll-like receptor (TLR) agonist.

The STING agonist can be any agonist of STING. In some embodiments, theSTING agonist is a cyclic dinucleotide (CDN). The CDN can be any CDN orderivative or variant thereof. In some embodiments, the STING agonist isa CDN selected from the group consisting of cGAMP, c-di-AMP, c-di-GMP,cAIMP, and c-di-IMP. In some embodiments, the STING agonist is aderivative or variant of a CDN selected from the group consisting ofcGAMP, c-di-AMP, c-di-GMP, cAIMP, and c-di-IMP. In some embodiments, theSTING agonist is4-(2-chloro-6-fluorobenzyl)-N-(furan-2-ylmethyl)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamide,or a derivative or variant thereof. See, e.g., Sali et al. (2015) PloSPathog., 11(12): e1005324.

The TLR agonist can be an agonist of any TLR, such as TLR1, TLR2, TLR3,TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, or TLR10. In some embodiments, theTLR agonist is an agonist of a TLR expressed on the cell surface, suchas TLR1, TLR2, TLR4, or TLR5. In some embodiments, the TLR agonist is anagonist of a TLR expressed intracellularly, such as TLR3, TLR7, TLR8,TLR9, or TLR10.

Conjugates of a masked cytokine and a cytotoxic agent may be made usinga variety of bifunctional protein coupling agents such asN-succinimidyl-3-(2-pyridyldithio) propionate (SPDP),succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC),iminothiolane (IT), bifunctional derivatives of imidoesters (such asdimethyl adipimidate HCl), active esters (such as disuccinimidylsuberate), aldehydes (such as glutaraldehyde), bis-azido compounds (suchas bis (p-azidobenzoyl) hexanediamine), bis-diazonium derivatives (suchas bis-(p-diazoniumbenzoyl)-ethylenediamine), diisocyanates (such astoluene 2,6-diisocyanate), and bis-active fluorine compounds (such as1,5-difluoro-2,4-dinitrobenzene). For example, a ricin immunotoxin canbe prepared as described in Vitetta et al., Science 238:1098 (1987).Carbon-14-labeled 1-isothiocyanatobenzyl-3-methyldiethylenetriaminepentaacetic acid (MX-DTPA) is an exemplary chelating agent forconjugation of radionucleotide to an antibody. See WO94/11026. Thelinker may be a “cleavable linker” facilitating release of a cytotoxicdrug in the cell. For example, an acid-labile linker,peptidase-sensitive linker, photolabile linker, dimethyl linker ordisulfide-containing linker (Chari et al., Cancer Res. 52:127-131(1992); U.S. Pat. No. 5,208,020) may be used.

The MCDCs herein expressly contemplate, but are not limited to suchconjugates prepared with cross-linker reagents including, but notlimited to, BMPS, EMCS, GMBS, HBVS, LC-SMCC, MBS, MPBH, SBAP, SIA, SIAB,SMCC, SMPB, SMPH, sulfo-EMCS, sulfo-GMBS, sulfo-KMUS, sulfo-MBS,sulfo-SIAB, sulfo-SMCC, and sulfo-SMPB, and SVSB(succinimidyl-(4-vinylsulfone)benzoate) which are commercially available(e.g., from Pierce Biotechnology, Inc., Rockford, Ill., U.S.A).

C. Vectors, Host Cells, and Recombinant Methods

For recombinant production of a masked cytokine of the invention, theone or more nucleic acids encoding it is isolated and inserted into areplicable vector for further cloning (amplification of the DNA) or forexpression. DNA encoding the masked cytokine, including componentsthereof, is readily isolated and sequenced using conventionalprocedures. Many vectors are available. The choice of vector depends inpart on the host cell to be used. Generally, host cells are of eitherprokaryotic or eukaryotic (generally mammalian) origin. It will beappreciated that constant regions of any isotype of antibody or fragmentthereof, when applicable, can be used for this purpose, including IgG,IgM, IgA, IgD, and IgE constant regions, and that such constant regionscan be obtained from any human or animal species. In some embodiments,one vector is used to encode the masked cytokine. In some embodiments,more than one vector is used to encode the masked cytokine.

1. Generating Masked Cytokines Using Prokaryotic Host Cells

a. Vector Construction

Polynucleotide sequences encoding polypeptide components of the maskedcytokines of the invention can be obtained using standard recombinanttechniques. Desired polynucleotide sequences of an antibody or antibodyfragment thereof may be isolated and sequenced from antibody producingcells such as hybridoma cells. Alternatively, polynucleotides can besynthesized using nucleotide synthesizer or PCR techniques, or obtainedfrom other sources. Once obtained, sequences encoding the components ofthe masked cytokine are inserted into a recombinant vector capable ofreplicating and expressing heterologous polynucleotides in prokaryotichosts. Many vectors that are available and known in the art can be usedfor the purpose of the present invention. Selection of an appropriatevector will depend mainly on the size of the nucleic acids to beinserted into the vector and the particular host cell to be transformedwith the vector. Each vector contains various components, depending onits function (amplification or expression of heterologouspolynucleotide, or both) and its compatibility with the particular hostcell in which it resides. The vector components generally include, butare not limited to: an origin of replication, a selection marker gene, apromoter, a ribosome binding site (RBS), a signal sequence, theheterologous nucleic acid insert and a transcription terminationsequence.

In general, plasmid vectors containing replicon and control sequenceswhich are derived from species compatible with the host cell are used inconnection with these hosts. The vector ordinarily carries a replicationsite, as well as marking sequences which are capable of providingphenotypic selection in transformed cells. For example, E. coli istypically transformed using pBR322, a plasmid derived from an E. colispecies. pBR322 contains genes-encoding ampicillin (Amp) andtetracycline (Tet) resistance and thus provides easy means foridentifying transformed cells. pBR322, its derivatives, or othermicrobial plasmids or bacteriophage may also contain, or be modified tocontain, promoters which can be used by the microbial organism forexpression of endogenous proteins. Examples of pBR322 derivatives usedfor expression of particular antibodies are described in detail inCarter et al., U.S. Pat. No. 5,648,237.

In addition, phage vectors containing replicon and control sequencesthat are compatible with the host microorganism can be used astransforming vectors in connection with these hosts. For example,bacteriophage such as λGEM.TM.-11 may be utilized in making arecombinant vector which can be used to transform susceptible host cellssuch as E. coli LE392.

The expression vector of the invention may comprise two or morepromoter-cistron pairs, encoding each of the polypeptide components. Apromoter is an untranslated regulatory sequence located upstream (5′) toa cistron that modulates its expression. Prokaryotic promoters typicallyfall into two classes, inducible and constitutive. Inducible promoter isa promoter that initiates increased levels of transcription of thecistron under its control in response to changes in the culturecondition, e.g. the presence or absence of a nutrient or a change intemperature.

A large number of promoters recognized by a variety of potential hostcells are well known. The selected promoter can be operably linked tocistron DNA encoding either chain of the masked cytokine by removing thepromoter from the source DNA via restriction enzyme digestion andinserting the isolated promoter sequence into the vector of theinvention. Both the native promoter sequence and many heterologouspromoters may be used to direct amplification and/or expression of thetarget genes. In some embodiments, heterologous promoters are utilized,as they generally permit greater transcription and higher yields ofexpressed target gene as compared to the native target polypeptidepromoter.

Promoters suitable for use with prokaryotic hosts include the PhoApromoter, the β-galactamase and lactose promoter systems, a tryptophan(trp) promoter system and hybrid promoters such as the tac or the trcpromoter. However, other promoters that are functional in bacteria (suchas other known bacterial or phage promoters) are suitable as well. Theirnucleotide sequences have been published, thereby enabling a skilledworker operably to ligate them to cistrons encoding, for example, thetarget light and heavy chains for masked cytokines comprising a lightand heavy chain (Siebenlist et al. (1980) Cell 20: 269) using linkers oradaptors to supply any required restriction sites.

In one aspect of the invention, each cistron within the recombinantvector comprises a secretion signal sequence component that directstranslocation of the expressed polypeptides across a membrane. Ingeneral, the signal sequence may be a component of the vector, or it maybe a part of the target polypeptide DNA that is inserted into thevector. The signal sequence selected for the purpose of this inventionshould be one that is recognized and processed (i.e. cleaved by a signalpeptidase) by the host cell. For prokaryotic host cells that do notrecognize and process the signal sequences native to the heterologouspolypeptides, the signal sequence is substituted by a prokaryotic signalsequence selected, for example, from the group consisting of thealkaline phosphatase, penicillinase, Ipp, or heat-stable enterotoxin II(STII) leaders, LamB, PhoE, PelB, OmpA and MBP. In one embodiment of theinvention, the signal sequences used in both cistrons of the expressionsystem are STII signal sequences or variants thereof.

In another aspect, the production of the polypeptide componentsaccording to the invention can occur in the cytoplasm of the host cell,and therefore does not require the presence of secretion signalsequences within each cistron. In that regard, for embodimentscomprising immunoglobulin light and heavy chains, for example, the lightand heavy chains are expressed with or without the sequences for themasking moiety, linker sequence, etc., folded and assembled to formfunctional immunoglobulins within the cytoplasm. Certain host strains(e.g., the E. coli trxB-strains) provide cytoplasm conditions that arefavorable for disulfide bond formation, thereby permitting properfolding and assembly of expressed protein subunits. Proba and PluckthunGene, 159:203 (1995).

Masked cytokines of the invention can also be produced by using anexpression system in which the quantitative ratio of expressedpolypeptide components can be modulated in order to maximize the yieldof secreted and properly assembled antibodies of the invention. Suchmodulation is accomplished at least in part by simultaneously modulatingtranslational strengths for the polypeptide components.

Prokaryotic host cells suitable for expressing masked cytokines of theinvention include Archaebacteria and Eubacteria, such as Gram-negativeor Gram-positive organisms. Examples of useful bacteria includeEscherichia (e.g., E. coli), Bacilli (e.g., B. subtilis),Enterobacteria, Pseudomonas species (e.g., P. aeruginosa), Salmonellatyphimurium, Serratia marcescans, Klebsiella, Proteus, Shigella,Rhizobia, Vitreoscilla, or Paracoccus. In one embodiment, gram-negativecells are used. In one embodiment, E. coli cells are used as hosts forthe invention. Examples of E. coli strains include strain W3110(Bachmann, Cellular and Molecular Biology, vol. 2 (Washington, D.C.:American Society for Microbiology, 1987), pp. 1190-1219; ATCC DepositNo. 27,325) and derivatives thereof, including strain 33D3 havinggenotype W3110 AfhuA (AtonA) ptr3 lac Iq lacL8 AompTA(nmpc-fepE) degP41kanR (U.S. Pat. No. 5,639,635). Other strains and derivatives thereof,such as E. coli 294 (ATCC 31,446), E. coli B, E. co16, 1776 (ATCC31,537) and E. coli RV308(ATCC 31,608) are also suitable. These examplesare illustrative rather than limiting. Methods for constructingderivatives of any of the above-mentioned bacteria having definedgenotypes are known in the art and described in, for example, Bass etal., Proteins, 8:309-314 (1990). It is generally necessary to select theappropriate bacteria taking into consideration replicability of thereplicon in the cells of a bacterium. For example, E. coli, Serratia, orSalmonella species can be suitably used as the host when well-knownplasmids such as pBR322, pBR325, pACYC177, or pKN410 are used to supplythe replicon. Typically, the host cell should secrete minimal amounts ofproteolytic enzymes, and additional protease inhibitors may desirably beincorporated in the cell culture.

b. Masked Cytokine Production

Host cells are transformed with the above-described expression vectorsand cultured in conventional nutrient media modified as appropriate forinducing promoters, selecting transformants, or amplifying the genesencoding the desired sequences.

Transformation means introducing DNA into the prokaryotic host so thatthe DNA is replicable, either as an extrachromosomal element or bychromosomal integrant. Depending on the host cell used, transformationis done using standard techniques appropriate to such cells. The calciumtreatment employing calcium chloride is generally used for bacterialcells that contain substantial cell-wall barriers. Another method fortransformation employs polyethylene glycol/DMSO. Yet another techniqueused is electroporation.

Prokaryotic cells used to produce the masked cytokines of the inventionare grown in media known in the art and suitable for culture of theselected host cells. Examples of suitable media include luria broth (LB)plus necessary nutrient supplements. In some embodiments, the media alsocontains a selection agent, chosen based on the construction of theexpression vector, to selectively permit growth of prokaryotic cellscontaining the expression vector. For example, ampicillin is added tomedia for growth of cells expressing ampicillin resistant gene.

Any necessary supplements besides carbon, nitrogen, and inorganicphosphate sources may also be included at appropriate concentrationsintroduced alone or as a mixture with another supplement or medium suchas a complex nitrogen source. Optionally, the culture medium may containone or more reducing agents selected from the group consisting ofglutathione, cysteine, cystamine, thioglycollate, dithioerythritol anddithiothreitol.

The prokaryotic host cells are cultured at suitable temperatures. Incertain embodiments, for E. coli growth, growth temperatures range fromabout 20° C. to about 39° C.; from about 25° C. to about 37° C.; orabout 30° C. The pH of the medium may be any pH ranging from about 5 toabout 9, depending mainly on the host organism. In certain embodiments,for E. coli, the pH is from about 6.8 to about 7.4, or about 7.0.

If an inducible promoter is used in the expression vector of theinvention, protein expression is induced under conditions suitable forthe activation of the promoter. In one aspect of the invention, PhoApromoters are used for controlling transcription of the polypeptides.Accordingly, the transformed host cells are cultured in aphosphate-limiting medium for induction. In certain embodiments, thephosphate-limiting medium is the C.R.A.P. medium (see, e.g., Simmons etal., J. Immunol. Methods (2002), 263:133-147). A variety of otherinducers may be used, according to the vector construct employed, as isknown in the art.

In one embodiment, the expressed masked cytokines of the presentinvention are secreted into and recovered from the periplasm of the hostcells. Protein recovery typically involves disrupting the microorganism,generally by such means as osmotic shock, sonication or lysis. Oncecells are disrupted, cell debris or whole cells may be removed bycentrifugation or filtration. The proteins may be further purified, forexample, by affinity resin chromatography. Alternatively, proteins canbe transported into the culture media and isolated therein. Cells may beremoved from the culture and the culture supernatant being filtered andconcentrated for further purification of the proteins produced. Theexpressed polypeptides can be further isolated and identified usingcommonly known methods such as polyacrylamide gel electrophoresis (PAGE)and Western blot assay.

In one aspect of the invention, masked cytokine production is conductedin large quantity by a fermentation process. Various large-scalefed-batch fermentation procedures are available for production ofrecombinant proteins. Large-scale fermentations have at least 1000liters of capacity, and in certain embodiments, about 1,000 to 100,000liters of capacity. These fermentors use agitator impellers todistribute oxygen and nutrients, especially glucose. Small scalefermentation refers generally to fermentation in a fermentor that is nomore than approximately 100 liters in volumetric capacity, and can rangefrom about 1 liter to about 100 liters.

In a fermentation process, induction of protein expression is typicallyinitiated after the cells have been grown under suitable conditions to adesired density, e.g., an OD550 of about 180-220, at which stage thecells are in the early stationary phase. A variety of inducers may beused, according to the vector construct employed, as is known in the artand described above. Cells may be grown for shorter periods prior toinduction. Cells are usually induced for about 12-50 hours, althoughlonger or shorter induction time may be used.

To improve the production yield and quality of the polypeptides of theinvention, various fermentation conditions can be modified. For example,to improve the proper assembly and folding of, for example, secretedantibody polypeptides, additional vectors overexpressing chaperoneproteins, such as Dsb proteins (DsbA, DsbB, DsbC, DsbD and or DsbG) orFkpA (a peptidylprolyl cis,trans-isomerase with chaperone activity) canbe used to co-transform the host prokaryotic cells. The chaperoneproteins have been demonstrated to facilitate the proper folding andsolubility of heterologous proteins produced in bacterial host cells.Chen et al. (1999) J. Biol. Chem. 274:19601-19605; Georgiou et al., U.S.Pat. No. 6,083,715; Georgiou et al., U.S. Pat. No. 6,027,888; Bothmannand Pluckthun (2000) J. Biol. Chem. 275:17100-17105; Ramm and Pluckthun(2000) J. Biol. Chem. 275:17106-17113; Arie et al. (2001) Mol.Microbiol. 39:199-210.

To minimize proteolysis of expressed heterologous proteins (especiallythose that are proteolytically sensitive), certain host strainsdeficient for proteolytic enzymes can be used for the present invention.For example, host cell strains may be modified to effect geneticmutation(s) in the genes encoding known bacterial proteases such asProtease III, OmpT, DegP, Tsp, Protease I, Protease Mi, Protease V,Protease VI and combinations thereof. Some E. coli protease-deficientstrains are available and described in, for example, Joly et al. (1998),supra; Georgiou et al., U.S. Pat. No. 5,264,365; Georgiou et al., U.S.Pat. No. 5,508,192; Hara et al., Microbial Drug Resistance, 2:63-72(1996).

In some embodiments, E. coli strains deficient for proteolytic enzymesand transformed with plasmids overexpressing one or more chaperoneproteins are used as host cells in the expression system of theinvention.

c. Masked Cytokine Purification

In some embodiments, the masked cytokine produced herein is furtherpurified to obtain preparations that are substantially homogeneous forfurther assays and uses. Standard protein purification methods known inthe art can be employed. The following procedures are exemplary ofsuitable purification procedures: fractionation on immunoaffinity orion-exchange columns, ethanol precipitation, reverse phase HPLC,chromatography on silica or on a cation-exchange resin such as DEAE,chromatofocusing, SDS-PAGE, ammonium sulfate precipitation, and gelfiltration using, for example, Sephadex G-75.

In some embodiments, Protein A immobilized on a solid phase is used forimmunoaffinity purification of the masked cytokines of the invention.Protein A is a 41 kD cell wall protein from Staphylococcus aureas whichbinds with a high affinity to the Fc region of antibodies. Lindmark etal (1983) J. Immunol. Meth. 62:1-13. The solid phase to which Protein Ais immobilized can be a column comprising a glass or silica surface, ora controlled pore glass column or a silicic acid column. In someapplications, the column is coated with a reagent, such as glycerol, topossibly prevent nonspecific adherence of contaminants.

As the first step of purification, a preparation derived from the cellculture as described above can be applied onto a Protein A immobilizedsolid phase to allow specific binding of the masked cytokine of interestto Protein A. The solid phase would then be washed to removecontaminants non-specifically bound to the solid phase. Finally, themasked cytokine of interest is recovered from the solid phase byelution.

Other methods of purification that provide for high affinity binding toa component of the masked cytokine can be employed in accordance withstandard protein purification methods known in the art.

2. Generating Masked Cytokines Using Eukaryotic Host Cells

A vector for use in a eukaryotic host cell generally includes one ormore of the following non-limiting components: a signal sequence, anorigin of replication, one or more marker genes, an enhancer element, apromoter, and a transcription termination sequence.

a. Signal Sequence Component

A vector for use in a eukaryotic host cell may also contain a signalsequence or other polypeptide having a specific cleavage site at theN-terminus of the mature protein or polypeptide of interest. Theheterologous signal sequence selected may be one that is recognized andprocessed (i.e., cleaved by a signal peptidase) by the host cell. Inmammalian cell expression, mammalian signal sequences as well as viralsecretory leaders, for example, the herpes simplex gD signal, areavailable. The DNA for such a precursor region is ligated in readingframe to DNA encoding the masked cytokine.

b. Origin of Replication

Generally, an origin of replication component is not needed formammalian expression vectors. For example, the SV40 origin may typicallybe used only because it contains the early promoter.

c. Selection Gene Component

Expression and cloning vectors may contain a selection gene, also termeda selectable marker. Typical selection genes encode proteins that (a)confer resistance to antibiotics or other toxins, e.g., ampicillin,neomycin, methotrexate, or tetracycline, (b) complement auxotrophicdeficiencies, where relevant, or (c) supply critical nutrients notavailable from complex media.

One example of a selection scheme utilizes a drug to arrest growth of ahost cell. Those cells that are successfully transformed with aheterologous gene produce a protein conferring drug resistance and thussurvive the selection regimen. Examples of such dominant selection usethe drugs neomycin, mycophenolic acid and hygromycin.

Another example of suitable selectable markers for mammalian cells arethose that enable the identification of cells competent to take up themasked cytokine encoding nucleic acid, such as DHFR, thymidine kinase,metallothionein-I and -II, primate metallothionein genes, adenosinedeaminase, ornithine decarboxylase, etc.

For example, in some embodiments, cells transformed with the DHFRselection gene are first identified by culturing all of thetransformants in a culture medium that contains methotrexate (Mtx), acompetitive antagonist of DHFR. In some embodiments, an appropriate hostcell when wild-type DHFR is employed is the Chinese hamster ovary (CHO)cell line deficient in DHFR activity (e.g., ATCC CRL-9096).

Alternatively, host cells (particularly wild-type hosts that containendogenous DHFR) transformed or co-transformed with DNA sequencesencoding a masked cytokine, wild-type DHFR protein, and anotherselectable marker such as aminoglycoside 3′-phosphotransferase (APH) canbe selected by cell growth in medium containing a selection agent forthe selectable marker such as an aminoglycosidic antibiotic, e.g.,kanamycin, neomycin, or G418. See U.S. Pat. No. 4,965,199. Host cellsmay include NSO, including cell lines deficient in glutamine synthetase(GS). Methods for the use of GS as a selectable marker for mammaliancells are described in U.S. Pat. Nos. 5,122,464 and 5,891,693.

d. Promoter Component

Expression and cloning vectors usually contain a promoter that isrecognized by the host organism and is operably linked to nucleic acidencoding a masked cytokine of interest, which can be any masked cytokinedescribed herein. Promoter sequences are known for eukaryotes. Forexample, virtually all eukaryotic genes have an AT-rich region locatedapproximately 25 to 30 bases upstream from the site where transcriptionis initiated. Another sequence found 70 to 80 bases upstream from thestart of transcription of many genes is a CNCAAT region where N may beany nucleotide. At the 3′ end of most eukaryotic genes is an AATAAAsequence that may be the signal for addition of the poly A tail to the3′ end of the coding sequence. In certain embodiments, any or all ofthese sequences may be suitably inserted into eukaryotic expressionvectors.

Transcription from vectors in mammalian host cells is controlled, forexample, by promoters obtained from the genomes of viruses such aspolyoma virus, fowlpox virus, adenovirus (such as Adenovirus 2), bovinepapilloma virus, avian sarcoma virus, cytomegalovirus, a retrovirus,hepatitis-B virus and Simian Virus 40 (SV40), from heterologousmammalian promoters, e.g., the actin promoter or an immunoglobulinpromoter, from heat-shock promoters, provided such promoters arecompatible with the host cell systems.

The early and late promoters of the SV40 virus are conveniently obtainedas an SV40 restriction fragment that also contains the SV40 viral originof replication. The immediate early promoter of the humancytomegalovirus is conveniently obtained as a Hindlll E restrictionfragment. A system for expressing DNA in mammalian hosts using thebovine papilloma virus as a vector is disclosed in U.S. Pat. No.4,419,446. A modification of this system is described in U.S. Pat. No.4,601,978. See also Reyes et al., Nature 297:598-601 (1982), describingexpression of human I3-interferon cDNA in murine cells under the controlof a thymidine kinase promoter from herpes simplex virus. Alternatively,the Rous Sarcoma Virus long terminal repeat can be used as the promoter.

e. Enhancer Element Component

Transcription of DNA encoding a masked cytokine of this invention byhigher eukaryotes is often increased by inserting an enhancer sequenceinto the vector. Many enhancer sequences are now known from mammaliangenes (globin, elastase, albumin, a-fetoprotein, and insulin).Typically, however, one will use an enhancer from a eukaryotic cellvirus. Examples include the SV40 enhancer on the late side of thereplication origin (bp 100-270), the human cytomegalovirus earlypromoter enhancer, the murine cytomegalovirus early promoter enhancer,the polyoma enhancer on the late side of the replication origin, andadenovirus enhancers. See also Yaniv, Nature 297:17-18 (1982)(describing enhancer elements for activation of eukaryotic promoters).The enhancer may be spliced into the vector at a position 5′ or 3′ tothe masked cytokine-encoding sequence, but is generally located at asite 5′ from the promoter.

f. Transcription Termination Component

Expression vectors used in eukaryotic host cells may also containsequences necessary for the termination of transcription and forstabilizing the mRNA. Such sequences are commonly available from the 5′and, occasionally 3′, untranslated regions of eukaryotic or viral DNAsor cDNAs. These regions contain nucleotide segments transcribed aspolyadenylated fragments in the untranslated portion of the mRNAencoding a masked cytokine. One useful transcription terminationcomponent is the bovine growth hormone polyadenylation region. SeeWO94/11026 and the expression vector disclosed therein.

g. Selection and Transformation of Host Cells

Suitable host cells for cloning or expressing the DNA in the vectorsherein include higher eukaryote cells described herein, includingvertebrate host cells. Propagation of vertebrate cells in culture(tissue culture) has become a routine procedure. Examples of usefulmammalian host cell lines are monkey kidney CV1 line transformed by SV40(COS-7, ATCC CRL 1651); human embryonic kidney line (293 or 293 cellssubcloned for growth in suspension culture, Graham et al., J. Gen Virol.36:59 (1977)); baby hamster kidney cells (BHK, ATCC CCL 10); Chinesehamster ovary cells/-DHFR (CHO, Urlaub et al., Proc. Natl. Acad. Sci.USA 77:4216 (1980)); murine sertoli cells (TM4, Mather, Biol. Reprod.23:243-251 (1980)); monkey kidney cells (CV1 ATCC CCL 70); African greenmonkey kidney cells (VERO-76, ATCC CRL-1587); human cervical carcinomacells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34);buffalo rat liver cells (BRL 3A, ATCC CRL 1442); human lung cells (W138,ATCC CCL 75); human liver cells (Hep G2, HB 8065); murine mammary tumor(MMT 060562, ATCC CCL51); TRI cells (Mather et al., Annals N.Y. Acad.Sci. 383:44-68 (1982)); MRC 5 cells; FS4 cells; and a human hepatomaline (Hep G2).

Host cells are transformed with the above-described-expression orcloning vectors for masked cytokine production and cultured inconventional nutrient media modified as appropriate for inducingpromoters, selecting transformants, or amplifying the genes encoding thedesired sequences.

h. Culturing Host Cells

The host cells used to produce masked cytokines of this invention may becultured in a variety of media. Commercially available media such asHam's F10 (Sigma), Minimal Essential Medium ((MEM), Sigma), RPMI-1640(Sigma), and Dulbecco's Modified Eagle's Medium ((DMEM), Sigma) aresuitable for culturing the host cells. In addition, any of the mediadescribed in Ham et al., Meth. Enz. 58:44 (1979), Barnes et al., Anal.Biochem. 102:255 (1980), U.S. Pat. Nos. 4,767,704; 4,657,866; 4,927,762;4,560,655; or 5,122,469; WO 90/03430; WO 87/00195; or U.S. Pat. Re.30,985 may be used as culture media for the host cells. Any of thesemedia may be supplemented as necessary with hormones and/or other growthfactors (such as insulin, transferrin, or epidermal growth factor),salts (such as sodium chloride, calcium, magnesium, and phosphate),buffers (such as HEPES), nucleotides (such as adenosine and thymidine),antibiotics (such as GENTAMYCIN™ drug), trace elements (defined asinorganic compounds usually present at final concentrations in themicromolar range), and glucose or an equivalent energy source. Any othersupplements may also be included at appropriate concentrations thatwould be known to those skilled in the art. The culture conditions, suchas temperature, pH, and the like, are those previously used with thehost cell selected for expression, and will be apparent to theordinarily skilled artisan.

i. Purification of Masked Cytokines

When using recombinant techniques, the masked cytokines can be producedintracellularly, or directly secreted into the medium. If the maskedcytokine is produced intracellularly, as a first step, the particulatedebris, either host cells or lysed fragments, may be removed, forexample, by centrifugation or ultrafiltration. Where the masked cytokineis secreted into the medium, supernatants from such expression systemsmay be first concentrated using a commercially available proteinconcentration filter, for example, an Amicon or Millipore Pelliconultrafiltration unit. A protease inhibitor such as PMSF may be includedin any of the foregoing steps to inhibit proteolysis, and antibioticsmay be included to prevent the growth of adventitious contaminants.

The masked cytokine composition prepared from the cells can be purifiedusing, for example, hydroxylapatite chromatography, gel electrophoresis,dialysis, and affinity chromatography, with affinity chromatographybeing a convenient technique. The suitability of protein A as anaffinity ligand depends on the species and isotype of any immunoglobulinFc domain, if any, that is present in the masked cytokine. Protein A canbe used to purify antibodies that are based on human IgG1, IgG2, or IgG4heavy chains (Lindmark et al., J. Immunol. Methods 62:1-13 (1983)).Protein G is recommended for all murine isotypes and for human γ3 (Gusset al., EMBO J. 5:15671575 (1986)). The matrix to which the affinityligand is attached may be agarose, but other matrices are available.Mechanically stable matrices such as controlled pore glass orpoly(styrenedivinyl)benzene allow for faster flow rates and shorterprocessing times than can be achieved with agarose. Where the maskedcytokine comprises a CH3 domain, the Bakerbond ABX™ resin (J. T. Baker,Phillipsburg, N.J.) is useful for purification. Other techniques forprotein purification such as fractionation on an ion-exchange column,ethanol precipitation, Reverse Phase HPLC, chromatography on silica,chromatography on heparin SEPHAROSE™ chromatography on an anion orcation exchange resin (such as a polyaspartic acid column),chromatofocusing, SDS-PAGE, and ammonium sulfate precipitation are alsoavailable depending on the masked cytokine to be recovered.

Following any preliminary purification step(s), the mixture comprisingthe masked cytokine of interest and contaminants may be subjected tofurther purification, for example, by low pH hydrophobic interactionchromatography using an elution buffer at a pH between about 2.5-4.5,performed at low salt concentrations (e.g., from about 0-0.25M salt).

In general, various methodologies for preparing masked cytokines for usein research, testing, and clinical use are well-established in the art,consistent with the above-described methodologies and/or as deemedappropriate by one skilled in the art for a particular masked cytokineof interest.

III. COMPOSITIONS

In some aspects, also provided herein are compositions comprising any ofthe masked cytokines described herein. In some embodiments, thecomposition comprises any of the exemplary embodiments of maskedcytokine described herein. In some embodiments, the compositioncomprises a dimer of any of the masked cytokines described herein. Insome embodiments, the composition is a pharmaceutical composition. Insome embodiments, the composition comprises a masked cytokine andfurther comprises one or more of the components as described in detailbelow. For example, in some embodiments, the composition comprises oneor more pharmaceutically acceptable carriers, excipients, stabilizers,buffers, preservatives, tonicity agents, non-ionic surfactants ordetergents, or other therapeutic agents or active compounds, orcombinations thereof. The various embodiments of the composition aresometimes referred to herein as formulations.

Therapeutic formulations are prepared for storage by mixing the activeingredient having the desired degree of purity with optionalpharmaceutically acceptable carriers, excipients or stabilizers(Remington: The Science and Practice of Pharmacy, 20th Ed., LippincottWilliams & Wiklins, Pub., Gennaro Ed., Philadelphia, Pa. 2000).Acceptable carriers, excipients, or stabilizers are nontoxic torecipients at the dosages and concentrations employed, and includebuffers, antioxidants including ascorbic acid, methionine, Vitamin E,sodium metabisulfite; preservatives, isotonicifiers, stabilizers, metalcomplexes (e.g. Zn-protein complexes); chelating agents such as EDTAand/or non-ionic surfactants.

Buffers can be used to control the pH in a range which optimizes thetherapeutic effectiveness, especially if stability is pH dependent.Buffers can be present at concentrations ranging from about 50 mM toabout 250 mM. Suitable buffering agents for use with the presentinvention include both organic and inorganic acids and salts thereof.For example, citrate, phosphate, succinate, tartrate, fumarate,gluconate, oxalate, lactate, acetate. Additionally, buffers may becomprised of histidine and trimethylamine salts such as Tris.

Preservatives can be added to prevent microbial growth, and aretypically present in a range from about 0.2%-1.0% (w/v). Examples ofsuitable preservatives commonly used with therapeutics includeoctadecyldimethylbenzyl ammonium chloride; hexamethonium chloride;benzalkonium halides (e.g., chloride, bromide, iodide), benzethoniumchloride; thimerosal, phenol, butyl or benzyl alcohol; alkyl parabenssuch as methyl or propyl paraben; catechol; resorcinol; cyclohexanol,3-pentanol, m-cresol, o-cresol, p-cresol, methyl p-hydroxybenzoate,propyl p-hydroxybenzoate, 2-phenoxyethanol, butyl p-hydroxybenzoate,2-phenylethanol, ethanol, chlorobutanol, thiomerosal, bronopol, benzoicacid, imidurea, chlorohexidine, sodium dehydroacetate, chlorocresol,ethyl p-hydroxybenzoate, and chlorphenesine(3p-chlorphenoxypropane-1,2-diol).

Tonicity agents, sometimes known as “stabilizers” can be present toadjust or maintain the tonicity of liquid in a composition. When usedwith large, charged biomolecules such as proteins and antibodies, theyare often termed “stabilizers” because they can interact with thecharged groups of the amino acid side chains, thereby lessening thepotential for inter and intra-molecular interactions. Tonicity agentscan be present in any amount between about 0.1% to about 25% by weightor between about 1 to about 5% by weight, taking into account therelative amounts of the other ingredients. In some embodiments, tonicityagents include polyhydric sugar alcohols, trihydric or higher sugaralcohols, such as glycerin, erythritol, arabitol, xylitol, sorbitol andmannitol.

Additional excipients include agents which can serve as one or more ofthe following: (1) bulking agents, (2) solubility enhancers, (3)stabilizers and (4) and agents preventing denaturation or adherence tothe container wall. Such excipients include: polyhydric sugar alcohols(enumerated above); amino acids such as alanine, glycine, glutamine,asparagine, histidine, arginine, lysine, ornithine, leucine,2-phenylalanine, glutamic acid, threonine, etc.; organic sugars or sugaralcohols such as sucrose, lactose, lactitol, trehalose, stachyose,mannose, sorbose, xylose, ribose, ribitol, myoinisitose, myoinisitol,galactose, galactitol, glycerol, cyclitols (e.g., inositol),polyethylene glycol; sulfur containing reducing agents, such as urea,glutathione, thioctic acid, sodium thioglycolate, thioglycerol,α-monothioglycerol and sodium thio sulfate; low molecular weightproteins such as human serum albumin, bovine serum albumin, gelatin orother immunoglobulins; hydrophilic polymers such aspolyvinylpyrrolidone; monosaccharides (e.g., xylose, mannose, fructose,glucose; disaccharides (e.g., lactose, maltose, sucrose); trisaccharidessuch as raffinose; and polysaccharides such as dextrin or dextran.

Non-ionic surfactants or detergents (also known as “wetting agents”) canbe present to help solubilize the therapeutic agent as well as toprotect the therapeutic protein against agitation-induced aggregation,which also permits the formulation to be exposed to shear surface stresswithout causing denaturation of the active therapeutic protein orantibody. Non-ionic surfactants are present in a range of about 0.05mg/ml to about 1.0 mg/ml or about 0.07 mg/ml to about 0.2 mg/ml. In someembodiments, non-ionic surfactants are present in a range of about0.001% to about 0.1% w/v or about 0.01% to about 0.1% w/v or about 0.01%to about 0.025% w/v.

Suitable non-ionic surfactants include polysorbates (20, 40, 60, 65, 80,etc.), polyoxamers (184, 188, etc.), PLURONIC® polyols, TRITON®,polyoxyethylene sorbitan monoethers (TWEEN®-20, TWEEN®-80, etc.),lauromacrogol 400, polyoxyl 40 stearate, polyoxyethylene hydrogenatedcastor oil 10, 50 and 60, glycerol monostearate, sucrose fatty acidester, methyl celluose and carboxymethyl cellulose. Anionic detergentsthat can be used include sodium lauryl sulfate, dioctyle sodiumsulfosuccinate and dioctyl sodium sulfonate. Cationic detergents includebenzalkonium chloride or benzethonium chloride.

In order for the formulations to be used for in vivo administration,they must be sterile. The formulation may be rendered sterile byfiltration through sterile filtration membranes. The therapeuticcompositions herein generally are placed into a container having asterile access port, for example, an intravenous solution bag or vialhaving a stopper pierceable by a hypodermic injection needle.

The route of administration is in accordance with known and acceptedmethods, such as by single or multiple bolus or infusion over a longperiod of time in a suitable manner, e.g., injection or infusion bysubcutaneous, intravenous, intraperitoneal, intramuscular,intraarterial, intralesional or intraarticular routes, topicaladministration, inhalation or by sustained release or extended-releasemeans.

Any of the masked cytokines described herein can be used alone or incombination with other therapeutic agents such is in the methodsdescribed herein. The term “in combination with” encompasses two or moretherapeutic agents (e.g., a masked cytokine and a therapeutic agent)that are included in the same or separate formulations. In someembodiments, “in combination with” refers to “simultaneous”administration, in which case administration of the masked cytokine ofthe invention occurs simultaneously to the administration of the one ormore additional therapeutic agents (e.g., at the same time or within onehour between administration(s) of the masked cytokine and administrationof the one or more additional therapeutic agents). In some embodiments,“in combination with” refers to sequential administration, in which caseadministration of the masked cytokine of the invention occurs prior toand/or following, administration of the one or more additionaltherapeutic agents (e.g., greater than one hour betweenadministration(s) of the masked cytokine and administration of the oneor more additional therapeutic agents). Agents contemplated hereininclude, but are not limited to, a cytotoxic agent, a cytokine, an agenttargeting an immune checkpoint molecule, an agent targeting an immunestimulatory molecule, a growth inhibitory agent, an immune stimulatoryagent, an anti-inflammatory agent, or an anti-cancer agent.

The formulation herein may also contain more than one active compound asnecessary for the particular indication being treated, preferably thosewith complementary activities that do not adversely affect each other.Alternatively, or in addition, the composition may comprise a cytotoxicagent, cytokine, agent targeting an immune checkpoint molecule orstimulatory molecule, growth inhibitory agent, an immune stimulatoryagent, an anti-inflammatory agent, or an anti-cancer agent. Suchmolecules are suitably present in combination in amounts that areeffective for the purpose intended.

The formulation may be presented in any suitable state, such as a liquidformulation, a solid state (lyophilized) formulation, or a frozenformulation. Approaches for preparing each of these types offormulations for therapeutic use are well known in the art.

IV. METHODS OF TREATMENT

Provided herein are methods for treating or preventing a disease in asubject comprising administering to the subject an effective amount ofany masked cytokine described herein or compositions thereof. In someembodiments, methods are provided for treating or preventing a diseasein a subject comprising administering to the subject an effective amountof a masked cytokine. In some embodiments, methods are provided fortreating or preventing a disease in a subject comprising administeringto the subject an effective amount of any embodiment of a maskedcytokine described herein. In some embodiments, methods are provided fortreating or preventing a disease in a subject comprising administeringto the subject any composition described herein. In some embodiments,the subject (e.g., a human patient) has been diagnosed with a neoplasticdisorder (e.g., cancer) or is at risk of developing such a disorder.

For the prevention or treatment of disease, the appropriate dosage of anactive agent will depend on the type of disease to be treated, asdefined herein, the severity and course of the disease, whether theagent is administered for preventive or therapeutic purposes, previoustherapy, the subject's clinical history and response to the agent, andthe discretion of the attending physician. The agent is suitablyadministered to the subject at one time or over a series of treatments.

In some embodiments of the methods described herein, an interval betweenadministrations of a masked cytokine described herein is about one weekor longer. In some embodiments of the methods described herein, aninterval between administrations of a masked cytokine described hereinis about two days or longer, about three days or longer, about four daysor longer, about five days or longer, or about six days or longer. Insome embodiments of the methods described herein, an interval betweenadministrations of a masked cytokine described herein is about one weekor longer, about two weeks or longer, about three weeks or longer, orabout four weeks or longer. In some embodiments of the methods describedherein, an interval between administrations of a masked cytokinedescribed herein is about one month or longer, about two months orlonger, or about three months or longer. As used herein, an intervalbetween administrations refers to the time period between oneadministration of the masked cytokine and the next administration of themasked cytokine. As used herein, an interval of about one month includesfour weeks. In some embodiments, the treatment includes multipleadministrations of the masked cytokine, wherein the interval betweenadministrations may vary. For example, in some embodiments, the intervalbetween the first administration and the second administration is aboutone week, and the intervals between the subsequent administrations areabout two weeks. In some embodiments, the interval between the firstadministration and the second administration is about two days, threedays, four days, or five days, or six days, and the intervals betweenthe subsequent administrations are about one week.

In some embodiments, the masked cytokine is administered on multipleoccasions over a period of time. The dosage that is administered to thesubject on multiple occasions can, in some embodiments, be the samedosage for each administration, or, in some embodiments, the maskedcytokine can be administered to the subject at two or more differentdosages. For example, in some embodiments, a masked cytokine isinitially administered at one dosage on one or more occasions and islater administered at a second dosage on one or more occasions beginningat a later time point.

In some embodiments, a masked cytokine described herein is administeredat a flat dose. In some embodiments, a masked cytokine described hereinis administered to a subject at a dosage from about 25 mg to about 500mg per dose. In some embodiments, the masked cytokine is administered toa subject at a dosage of about 25 mg to about 50 mg, about 50 mg toabout 75 mg, about 75 mg to about 100 mg, about 100 mg to about 125 mg,about 125 mg to about 150 mg, about 150 mg to about 175 mg, about 175 mgto about 200 mg, about 200 mg to about 225 mg, about 225 mg to about 250mg, about 250 mg to about 275 mg, about 275 mg to about 300 mg, about300 mg to about 325 mg, about 325 mg to about 350 mg, about 350 mg toabout 375 mg, about 375 mg to about 400 mg, about 400 mg to about 425mg, about 425 mg to about 450 mg, about 450 mg, to about 475 mg, orabout 475 mg to about 500 mg per dose.

In some embodiments, a masked cytokine described herein is administeredto a subject at a dosage based on the subject's weight or body surfacearea (BSA). Depending on the type and severity of the disease, about 1μg/kg to 15 mg/kg (e.g. 0.1 mg/kg-10 mg/kg) of masked cytokine can be aninitial candidate dosage for administration to the patient, whether, forexample, by one or more separate administrations, or by continuousinfusion. One typical daily dosage might range from about 1 μg/kg to 100mg/kg or more, depending on the factors mentioned above. For repeatedadministrations over several days or longer, depending on the condition,the treatment would generally be sustained until a desired suppressionof disease symptoms occurs. One exemplary dosage of the masked cytokinewould be in the range from about 0.05 mg/kg to about 10 mg/kg. Thus, oneor more doses of about 0.5 mg/kg, 2.0 mg/kg, 4.0 mg/kg or 10 mg/kg (orany combination thereof) may be administered to the patient. In someembodiments, a masked cytokine described herein is administered to asubject at a dosage from about 0.1 mg/kg to about 10 mg/kg or about 1.0mg/kg to about 10 mg/kg. In some embodiments, a masked cytokinedescribed herein is administered to a subject at a dosage of about anyof 0.1 mg/kg, 0.5 mg/kg, 1.0 mg/kg, 1.5 mg/kg, 2.0 mg/kg, 2.5 mg/kg, 3.0mg/kg, 3.5 mg/kg, 4.0 mg/kg, 4.5 mg/kg, 5.0 mg/kg, 5.5 mg/kg, 6.0 mg/kg,6.5 mg/kg, 7.0 mg/kg, 7.5 mg/kg, 8.0 mg/kg, 8.5 mg/kg, 9.0 mg/kg, 9.5mg/kg, or 10.0 mg/kg. In some embodiments, a masked cytokine describedherein is administered to a subject at a dosage of about or at leastabout 0.1 mg/kg, about or at least about 0.5 mg/kg, about or at leastabout 1.0 mg/kg, about or at least about 1.5 mg/kg, about or at leastabout 2.0 mg/kg, about or at least about 2.5 mg/kg, about or at leastabout 3.0 mg/kg, about or at least about 3.5 mg/kg, about or at leastabout 4.0 mg/kg, about or at least about 4.5 mg/kg, about or at leastabout 5.0 mg/kg, about or at least about 5.5 mg/kg, about or at leastabout 6.0 mg/kg, about or at least about 6.5 mg/kg, about or at leastabout 7.0 mg/kg, about or at least about 7.5 mg/kg, about or at leastabout 8.0 mg/kg, about or at least about 8.5 mg/kg, about or at leastabout 9.0 mg/kg, about or at least about 9.5 mg/kg, about or at leastabout 10.0 mg/kg, about or at least about 15.0 mg/kg, about or at leastabout 20 mg/kg, about or at least about 30 mg/kg, about or at leastabout 40 mg/kg, about or at least about 50 mg/kg, about or at leastabout 60 mg/kg, about or at least about 70 mg/kg, about or at leastabout 80 mg/kg, about or at least about 90 mg/kg, or about or at leastabout 100 mg/kg. Any of the dosing frequencies described above may beused.

In some embodiments, a masked IL-2 polypeptide described herein isadministered at a flat dose. In some embodiments, a masked IL-2polypeptide described herein is administered to a subject at a dosagefrom about 25 mg to about 500 mg per dose. In some embodiments, themasked IL-2 polypeptide is administered to a subject at a dosage ofabout 25 mg to about 50 mg, about 50 mg to about 75 mg, about 75 mg toabout 100 mg, about 100 mg to about 125 mg, about 125 mg to about 150mg, about 150 mg to about 175 mg, about 175 mg to about 200 mg, about200 mg to about 225 mg, about 225 mg to about 250 mg, about 250 mg toabout 275 mg, about 275 mg to about 300 mg, about 300 mg to about 325mg, about 325 mg to about 350 mg, about 350 mg to about 375 mg, about375 mg to about 400 mg, about 400 mg to about 425 mg, about 425 mt toabout 450 mg, about 450 mg, to about 475 mg, or about 475 mg to about500 mg per dose.

In some embodiments, a masked IL-2 polypeptide described herein isadministered to a subject at a dosage based on the subject's weight orbody surface area (BSA). Depending on the type and severity of thedisease, about 1 μg/kg to 15 mg/kg (e.g. 0.1 mg/kg-10 mg/kg) of maskedIL-2 polypeptide can be an initial candidate dosage for administrationto the patient, whether, for example, by one or more separateadministrations, or by continuous infusion. One typical daily dosagemight range from about 1 μg/kg to 100 mg/kg or more, depending on thefactors mentioned above. For repeated administrations over several daysor longer, depending on the condition, the treatment would generally besustained until a desired suppression of disease symptoms occurs. Oneexemplary dosage of the masked IL-2 polypeptide would be in the rangefrom about 0.05 mg/kg to about 10 mg/kg. Thus, one or more doses ofabout 0.5 mg/kg, 2.0 mg/kg, 4.0 mg/kg or 10 mg/kg (or any combinationthereof) may be administered to the patient. In some embodiments, amasked IL-2 polypeptide described herein is administered to a subject ata dosage from about 0.1 mg/kg to about 10 mg/kg or about 1.0 mg/kg toabout 10 mg/kg. In some embodiments, a masked IL-2 polypeptide describedherein is administered to a subject at a dosage of about any of 0.1mg/kg, 0.5 mg/kg, 1.0 mg/kg, 1.5 mg/kg, 2.0 mg/kg, 2.5 mg/kg, 3.0 mg/kg,3.5 mg/kg, 4.0 mg/kg, 4.5 mg/kg, 5.0 mg/kg, 5.5 mg/kg, 6.0 mg/kg, 6.5mg/kg, 7.0 mg/kg, 7.5 mg/kg, 8.0 mg/kg, 8.5 mg/kg, 9.0 mg/kg, 9.5 mg/kg,or 10.0 mg/kg. In some embodiments, a masked IL-2 polypeptide describedherein is administered to a subject at a dosage of about or at leastabout 0.1 mg/kg, about or at least about 0.5 mg/kg, about or at leastabout 1.0 mg/kg, about or at least about 1.5 mg/kg, about or at leastabout 2.0 mg/kg, about or at least about 2.5 mg/kg, about or at leastabout 3.0 mg/kg, about or at least about 3.5 mg/kg, about or at leastabout 4.0 mg/kg, about or at least about 4.5 mg/kg, about or at leastabout 5.0 mg/kg, about or at least about 5.5 mg/kg, about or at leastabout 6.0 mg/kg, about or at least about 6.5 mg/kg, about or at leastabout 7.0 mg/kg, about or at least about 7.5 mg/kg, about or at leastabout 8.0 mg/kg, about or at least about 8.5 mg/kg, about or at leastabout 9.0 mg/kg, about or at least about 9.5 mg/kg, about or at leastabout 10.0 mg/kg, about or at least about 15.0 mg/kg, about or at leastabout 20 mg/kg, about or at least about 30 mg/kg, about or at leastabout 40 mg/kg, about or at least about 50 mg/kg, about or at leastabout 60 mg/kg, about or at least about 70 mg/kg, about or at leastabout 80 mg/kg, about or at least about 90 mg/kg, or about or at leastabout 100 mg/kg. Any of the dosing frequencies described above may beused.

In some embodiments, a masked IL-15 polypeptide described herein isadministered at a flat dose. In some embodiments, a masked IL-15polypeptide described herein is administered to a subject at a dosagefrom about 25 mg to about 500 mg per dose. In some embodiments, themasked IL-15 polypeptide is administered to a subject at a dosage ofabout 25 mg to about 50 mg, about 50 mg to about 75 mg, about 75 mg toabout 100 mg, about 100 mg to about 125 mg, about 125 mg to about 150mg, about 150 mg to about 175 mg, about 175 mg to about 200 mg, about200 mg to about 225 mg, about 225 mg to about 250 mg, about 250 mg toabout 275 mg, about 275 mg to about 300 mg, about 300 mg to about 325mg, about 325 mg to about 350 mg, about 350 mg to about 375 mg, about375 mg to about 400 mg, about 400 mg to about 425 mg, about 425 mg toabout 450 mg, about 450 mg, to about 475 mg, or about 475 mg to about500 mg per dose.

In some embodiments, a masked IL-15 polypeptide described herein isadministered to a subject at a dosage based on the subject's weight orbody surface area (BSA). Depending on the type and severity of thedisease, about 1 μg/kg to 15 mg/kg (e.g. 0.1 mg/kg-10 mg/kg) of maskedIL-15 polypeptide can be an initial candidate dosage for administrationto the patient, whether, for example, by one or more separateadministrations, or by continuous infusion. One typical daily dosagemight range from about 1 1 ug/kg to 100 mg/kg or more, depending on thefactors mentioned above. For repeated administrations over several daysor longer, depending on the condition, the treatment would generally besustained until a desired suppression of disease symptoms occurs. Thus,one or more doses of about 0.5 mg/kg, 2.0 mg/kg, 4.0 mg/kg or 10 mg/kg(or any combination thereof) may be administered to the patient. In someembodiments, a masked IL-15 polypeptide described herein is administeredto a subject at a dosage from about 25 mg to about 500 mg per dose. Insome embodiments, a masked IL-15 polypeptide described herein isadministered to a subject at a dosage from about 0.1 mg/kg to about 10mg/kg or about 1.0 mg/kg to about 10 mg/kg. In some embodiments, amasked IL-15 polypeptide described herein is administered to a subjectat a dosage of about any of 0.1 mg/kg, 0.5 mg/kg, 1.0 mg/kg, 1.5 mg/kg,2.0 mg/kg, 2.5 mg/kg, 3.0 mg/kg, 3.5 mg/kg, 4.0 mg/kg, 4.5 mg/kg, 5.0mg/kg, 5.5 mg/kg, 6.0 mg/kg, 6.5 mg/kg, 7.0 mg/kg, 7.5 mg/kg, 8.0 mg/kg,8.5 mg/kg, 9.0 mg/kg, 9.5 mg/kg, or 10.0 mg/kg. In some embodiments, amasked IL-15 polypeptide described herein is administered to a subjectat a dosage of about or at least about 0.1 mg/kg, about or at leastabout 0.5 mg/kg, about or at least about 1.0 mg/kg, about or at leastabout 1.5 mg/kg, about or at least about 2.0 mg/kg, about or at leastabout 2.5 mg/kg, about or at least about 3.0 mg/kg, about or at leastabout 3.5 mg/kg, about or at least about 4.0 mg/kg, about or at leastabout 4.5 mg/kg, about or at least about 5.0 mg/kg, about or at leastabout 5.5 mg/kg, about or at least about 6.0 mg/kg, about or at leastabout 6.5 mg/kg, about or at least about 7.0 mg/kg, about or at leastabout 7.5 mg/kg, about or at least about 8.0 mg/kg, about or at leastabout 8.5 mg/kg, about or at least about 9.0 mg/kg, about or at leastabout 9.5 mg/kg, about or at least about 10.0 mg/kg, about or at leastabout 15.0 mg/kg, about or at least about 20 mg/kg, about or at leastabout 30 mg/kg, about or at least about 40 mg/kg, about or at leastabout 50 mg/kg, about or at least about 60 mg/kg, about or at leastabout 70 mg/kg, about or at least about 80 mg/kg, about or at leastabout 90 mg/kg, or about or at least about 100 mg/kg. Any of the dosingfrequencies described above may be used.

A method of treatment contemplated herein is the treatment of a disorderor disease with any of the masked cytokines or compositions describedherein. In some embodiments, the method of treatment uses any maskedIL-2 polypeptide described herein, or any masked IL-15 polypeptidedescribed herein, or any of the compositions comprising a maskedcytokine described herein. Disorders or diseases that are treatable withthe formulations of this present invention include leukemia, lymphoma,head and neck cancer, colorectal cancer, prostate cancer, pancreaticcancer, melanoma, breast cancer, neuroblastoma, lung cancer, ovariancancer, osteosarcoma, bladder cancer, cervical cancer, liver cancer,kidney cancer, skin cancer (e.g., Merkel cell carcinoma) or testicularcancer.

In some embodiments, provided herein is a method of treatment orprevention of a cancer by administration of any masked cytokines orcompositions described herein. In some embodiments, provided herein is amethod of treatment or prevention of a cancer by administration of amasked IL-2 polypeptide, or a masked IL-15 polypeptide, or any of thecompositions comprising a masked cytokine described herein. As usedherein, the term “cancer” refers to all types of cancer, neoplasm ormalignant tumors found in mammals, including leukemias, lymphomas,melanomas, neuroendocrine tumors, carcinomas and sarcomas. Exemplarycancers that may be treated with a masked cytokine, pharmaceuticalcomposition, or method provided herein, include lymphoma, sarcoma,bladder cancer, bone cancer, brain tumor, cervical cancer, colon cancer,esophageal cancer, gastric cancer, head and neck cancer, kidney cancer,myeloma, thyroid cancer, leukemia, prostate cancer, breast cancer (e.g.triple negative, ER positive, ER negative, chemotherapy resistant,Herceptin resistant, HER2 positive, doxorubicin resistant, tamoxifenresistant, ductal carcinoma, lobular carcinoma, primary, metastatic),ovarian cancer, pancreatic cancer, liver cancer (e.g. hepatocellularcarcinoma), lung cancer (e.g. non-small cell lung carcinoma, squamouscell lung carcinoma, adenocarcinoma, large cell lung carcinoma, smallcell lung carcinoma, carcinoid, sarcoma), glioblastoma multiforme,glioma, melanoma, prostate cancer, castration-resistant prostate cancer,breast cancer, triple negative breast cancer, glioblastoma, ovariancancer, lung cancer, squamous cell carcinoma (e.g., head, neck, oresophagus), colorectal cancer, leukemia, acute myeloid leukemia,lymphoma, B cell lymphoma, or multiple myeloma. Additional examplesinclude, cancer of the thyroid, endocrine system, brain, breast, cervix,colon, head & neck, esophagus, liver, kidney, lung, non-small cell lung,melanoma, mesothelioma, ovary, sarcoma, stomach, uterus orMedulloblastoma, Hodgkin's Disease, Non-Hodgkin's Lymphoma, multiplemyeloma, neuroblastoma, glioma, glioblastoma multiforme, ovarian cancer,rhabdomyosarcoma, primary thrombocytosis, primary macroglobulinemia,primary brain tumors, cancer, malignant pancreatic insulanoma, malignantcarcinoid, urinary bladder cancer, premalignant skin lesions, testicularcancer, lymphomas, thyroid cancer, neuroblastoma, esophageal cancer,genitourinary tract cancer, malignant hypercalcemia, endometrial cancer,adrenal cortical cancer, neoplasms of the endocrine or exocrinepancreas, medullary thyroid cancer, medullary thyroid carcinoma,melanoma, colorectal cancer, papillary thyroid cancer, hepatocellularcarcinoma, Paget's Disease of the Nipple, Phyllodes Tumors, LobularCarcinoma, Ductal Carcinoma, cancer of the pancreatic stellate cells,cancer of the hepatic stellate cells, or prostate cancer.

In some embodiments, provided herein is a method of treatment orprevention of a leukemia by administration of any masked cytokine orcomposition described herein. The term “leukemia” refers broadly toprogressive, malignant diseases of the blood-forming organs and isgenerally characterized by a distorted proliferation and development ofleukocytes and their precursors in the blood and bone marrow. Leukemiais generally clinically classified on the basis of (1) the duration andcharacter of the disease-acute or chronic; (2) the type of cellinvolved; myeloid (myelogenous), lymphoid (lymphogenous), or monocytic;and (3) the increase or non-increase in the number abnormal cells in theblood-leukemic or aleukemic (subleukemic). Exemplary leukemias that maybe treated with a compound, pharmaceutical composition, or methodprovided herein include, for example, acute nonlymphocytic leukemia,chronic lymphocytic leukemia, acute granulocytic leukemia, chronicgranulocytic leukemia, acute promyelocytic leukemia, adult T-cellleukemia, aleukemic leukemia, a leukocythemic leukemia, basophylicleukemia, blast cell leukemia, bovine leukemia, chronic myelocyticleukemia, leukemia cutis, embryonal leukemia, eosinophilic leukemia,Gross' leukemia, hairy-cell leukemia, hemoblastic leukemia,hemocytoblastic leukemia, histiocytic leukemia, stem cell leukemia,acute monocytic leukemia, leukopenic leukemia, lymphatic leukemia,lymphoblastic leukemia, lymphocytic leukemia, lymphogenous leukemia,lymphoid leukemia, lymphosarcoma cell leukemia, mast cell leukemia,megakaryocytic leukemia, micromyeloblastic leukemia, monocytic leukemia,myeloblastic leukemia, myelocytic leukemia, myeloid granulocyticleukemia, myelomonocytic leukemia, Naegeli leukemia, plasma cellleukemia, multiple myeloma, plasmacytic leukemia, promyelocyticleukemia, Rieder cell leukemia, Schilling's leukemia, stem cellleukemia, subleukemic leukemia, or undifferentiated cell leukemia.

In some embodiments, provided herein is a method of treatment orprevention of a sarcoma by administration of any masked cytokine orcomposition described herein. The term “sarcoma” generally refers to atumor which is made up of a substance like the embryonic connectivetissue and is generally composed of closely packed cells embedded in afibrillar or homogeneous substance. Sarcomas that may be treated with acompound, pharmaceutical composition, or method provided herein includea chondrosarcoma, fibrosarcoma, lymphosarcoma, melanosarcoma,myxosarcoma, osteosarcoma, Abemethy's sarcoma, adipose sarcoma,liposarcoma, alveolar soft part sarcoma, ameloblastic sarcoma, botryoidsarcoma, chloroma sarcoma, chorio carcinoma, embryonal sarcoma, Wilms'tumor sarcoma, endometrial sarcoma, stromal sarcoma, Ewing's sarcoma,fascial sarcoma, fibroblastic sarcoma, giant cell sarcoma, granulocyticsarcoma, Hodgkin's sarcoma, idiopathic multiple pigmented hemorrhagicsarcoma, immunoblastic sarcoma of B cells, lymphoma, immunoblasticsarcoma of T-cells, Jensen's sarcoma, Kaposi's sarcoma, Kupffer cellsarcoma, angiosarcoma, leukosarcoma, malignant mesenchymoma sarcoma,parosteal sarcoma, reticulocytic sarcoma, Rous sarcoma, serocysticsarcoma, synovial sarcoma, or telangiectaltic sarcoma.

In some embodiments, provided herein is a method of treatment orprevention of a melanoma by administration of any masked cytokine orcomposition described herein. The term “melanoma” is taken to mean atumor arising from the melanocytic system of the skin and other organs.Melanomas that may be treated with a compound, pharmaceuticalcomposition, or method provided herein include, for example,acral-lentiginous melanoma, amelanotic melanoma, benign juvenilemelanoma, Cloudman's melanoma, S91 melanoma, Harding-Passey melanoma,juvenile melanoma, lentigo maligna melanoma, malignant melanoma, nodularmelanoma, subungal melanoma, or superficial spreading melanoma.

In some embodiments, provided herein is a method of treatment orprevention of a carcinoma by administration of any masked cytokine orcomposition described herein. The term “carcinoma” refers to a malignantnew growth made up of epithelial cells tending to infiltrate thesurrounding tissues and give rise to metastases. Exemplary carcinomasthat may be treated with a compound, pharmaceutical composition, ormethod provided herein include, for example, medullary thyroidcarcinoma, familial medullary thyroid carcinoma, acinar carcinoma,acinous carcinoma, adenocystic carcinoma, adenoid cystic carcinoma,carcinoma adenomatosum, carcinoma of adrenal cortex, alveolar carcinoma,alveolar cell carcinoma, basal cell carcinoma, carcinoma basocellulare,basaloid carcinoma, basosquamous cell carcinoma, bronchioalveolarcarcinoma, bronchiolar carcinoma, bronchogenic carcinoma, cerebriformcarcinoma, cholangiocellular carcinoma, chorionic carcinoma, colloidcarcinoma, comedo carcinoma, corpus carcinoma, cribriform carcinoma,carcinoma en cuirasse, carcinoma cutaneum, cylindrical carcinoma,cylindrical cell carcinoma, duct carcinoma, ductal carcinoma, carcinomadurum, embryonal carcinoma, encephaloid carcinoma, epiermoid carcinoma,carcinoma epitheliale adenoides, exophytic carcinoma, carcinoma exulcere, carcinoma fibrosum, gelatiniforni carcinoma, gelatinouscarcinoma, giant cell carcinoma, carcinoma gigantocellulare, glandularcarcinoma, granulosa cell carcinoma, hair-matrix carcinoma, hematoidcarcinoma, hepatocellular carcinoma, Hurthle cell carcinoma, hyalinecarcinoma, hypernephroid carcinoma, infantile embryonal carcinoma,carcinoma in situ, intraepidermal carcinoma, intraepithelial carcinoma,Krompecher's carcinoma, Kulchitzky-cell carcinoma, large-cell carcinoma,lenticular carcinoma, carcinoma lenticulare, lipomatous carcinoma,lobular carcinoma, lymphoepithelial carcinoma, carcinoma medullare,medullary carcinoma, melanotic carcinoma, carcinoma molle, mucinouscarcinoma, carcinoma muciparum, carcinoma mucocellulare, mucoepidermoidcarcinoma, carcinoma mucosum, mucous carcinoma, carcinoma myxomatodes,nasopharyngeal carcinoma, oat cell carcinoma, carcinoma ossificans,osteoid carcinoma, papillary carcinoma, periportal carcinoma,preinvasive carcinoma, prickle cell carcinoma, pultaceous carcinoma,renal cell carcinoma of kidney, reserve cell carcinoma, carcinomasarcomatodes, schneiderian carcinoma, scirrhous carcinoma, carcinomascroti, signet-ring cell carcinoma, carcinoma simplex, small-cellcarcinoma, solanoid carcinoma, spheroidal cell carcinoma, spindle cellcarcinoma, carcinoma spongiosum, squamous carcinoma, squamous cellcarcinoma, string carcinoma, carcinoma telangiectaticum, carcinomatelangiectodes, transitional cell carcinoma, carcinoma tuberosum,tubular carcinoma, tuberous carcinoma, verrucous carcinoma, or carcinomavillosum.

In some embodiments, provided herein is a method of treatment orprevention of metastatic cancer by administration of any masked cytokineor composition described herein. As used herein, the terms “metastasis,”“metastatic,” and “metastatic cancer” can be used interchangeably andrefer to the spread of a neoplastic disease or disorder, e.g., cancer,from one organ or another non-adjacent organ or body part. Cancer occursat an originating site, e.g., breast, which site is referred to as aprimary tumor, e.g., primary breast cancer. Some cancer cells in theprimary tumor or originating site acquire the ability to penetrate andinfiltrate surrounding normal tissue in the local area and/or theability to penetrate the walls of the lymphatic system or vascularsystem circulating through the system to other sites and tissues in thebody. A second clinically detectable tumor formed from cancer cells of aprimary tumor is referred to as a metastatic or secondary tumor. Whencancer cells metastasize, the metastatic tumor and its cells arepresumed to be similar to those of the original tumor. Thus, if lungcancer metastasizes to the breast, the secondary tumor at the site ofthe breast consists of abnormal lung cells and not abnormal breastcells. The secondary tumor in the breast is referred to a metastaticlung cancer. Thus, the phrase metastatic cancer refers to a disease inwhich a subject has or had a primary tumor and has one or more secondarytumors. The phrases non-metastatic cancer or subjects with cancer thatis not metastatic refers to diseases in which subjects have a primarytumor but not one or more secondary tumors. For example, metastatic lungcancer refers to a disease in a subject with or with a history of aprimary lung tumor and with one or more secondary tumors at a secondlocation or multiple locations, e.g., in the breast.

In some embodiments, provided herein is a method of treatment orprevention of a cancer by administration of any masked cytokine orcomposition described herein in combination with an anti-cancer agent.The anti-cancer agent can be any agent capable of reducing cancergrowth, interfering with cancer cell replication, directly or indirectlykilling cancer cells, reducing metastasis, reducing tumor blood supply,or reducing cell survival. In some embodiments, the anti-cancer agent isselected from the group consisting of a PD-1 inhibitor, an EGFRinhibitor, a HER2 inhibitor, a VEGFR inhibitor, a CTLA-4 inhibitor, aBTLA inhibitor, a B7H4 inhibitor, a B7H3 inhibitor, a CSFIR inhibitor,an HVEM inhibitor, a CD27 inhibitor, a KIR inhibitor, an NKG2Ainhibitor, an NKG2D agonist, a TWEAK inhibitor, an ALK inhibitor, a CD52targeting antibody, a CCR4 targeting antibody, a PD-L1 inhibitor, a KITinhibitor, a PDGFR inhibitor, a BAFF inhibitor, an HDAC inhibitor, aVEGF ligand inhibitor, a CD19 targeting molecule, a FOLR1 targetingmolecule, a DLL3 targeting molecule, a DKK1 targeting molecule, a MUC1targeting molecule, a MUC16 targeting molecule, a PSMA targetingmolecule, an MSLN targeting molecule, an NY-ESO-1 targeting molecule, aB7H3 targeting molecule, a B7H4 targeting molecule, a BCMA targetingmolecule, a CD29 targeting molecule, a CD151 targeting molecule, a CD123targeting molecule, a CD33 targeting molecule, a CD37 targetingmolecule, a CDH19 targeting molecule, a CEA targeting molecule, aClaudin 18.2 targeting molecule, a CLEC12A targeting molecule, anEGFRVIII targeting molecule, an EPCAM targeting molecule, an EPHA2targeting molecule, an FCRH5 targeting molecule, an FLT3 targetingmolecule, a GD2 targeting molecule, a glypican 3 targeting molecule, agpA33 targeting molecule, a GPRC5D targeting molecule, an IL-23Rtargeting molecule, an IL-1RAP targeting molecule, a MCSP targetingmolecule, a RON targeting molecule, a ROR1 targeting molecule, a STEAP2targeting molecule, a TfR targeting molecule, a CD166 targetingmolecule, a TPBG targeting molecule, a TROP2 targeting molecule, aproteasome inhibitor, an ABL inhibitor, a CD30 inhibitor, a FLT3inhibitor, a MET inhibitor, a RET inhibitor, an IL-113 inhibitor, a MEKinhibitor, a ROS1 inhibitor, a BRAF inhibitor, a CD38 inhibitor, a RANKLinhibitor, a B4GALNT1 inhibitor, a SLAMF7 inhibitor, an IDH2 inhibitor,an mTOR inhibitor, a CD20 targeting antibody, a BTK inhibitor, a PI3Kinhibitor, a FLT3 inhibitor, a PARP inhibitor, a CDK4 inhibitor, a CDK6inhibitor, an FGFR inhibitor, a RAF inhibitor, a JAK1 inhibitor, a JAK2inhibitor, a JAK3 inhibitor, an IL-6 inhibitor, a IL-17 inhibitor, aSmoothened inhibitor, an IL-6R inhibitor, a BCL2 inhibitor, a PTCHinhibitor, a PIGF inhibitor, a TGFB inhibitor, a CD28 agonist, a CD3agonist, CD40 agonist, a GITR agonist, a OX40 agonist, a VISTA agonist,a CD137 agonist, a LAG3 inhibitor, a TIM3 inhibitor, a TIGIT inhibitor,and an IL-2R inhibitor.

In some embodiments, provided herein is a method of treatment orprevention of a cancer by administration of any masked cytokinedescribed herein in combination with an anti-inflammatory agent. Theanti-inflammatory agent can be any agent capable of preventing,counteracting, inhibiting, or otherwise reducing inflammation.

In some embodiments, the anti-inflammatory agent is a cyclooxygenase(COX) inhibitor. The COX inhibitor can be any agent that inhibits theactivity of COX-1 and/or COX-2. In some embodiments, the COX inhibitorselectively inhibits COX-1 (i.e., the COX inhibitor inhibits theactivity of COX-1 more than it inhibits the activity of COX-2). In someembodiments, the COX inhibitor selectively inhibits COX-2 (i.e., the COXinhibitor inhibits the activity of COX-2 more than it inhibits theactivity of COX-1). In some embodiments, the COX inhibitor inhibits bothCOX-1 and COX-2.

In some embodiments, the COX inhibitor is a selective COX-1 inhibitorand is selected from the group consisting of SC-560, FR122047, P6,mofezolac, TFAP, flurbiprofen, and ketoprofen. In some embodiments, theCOX inhibitor is a selective COX-2 inhibitor and is selected from thegroup consisting of celecoxib, rofecoxib, meloxicam, piroxicam,deracoxib, parecoxib, valdecoxib, etoricoxib, a chromene derivative, achroman derivative, N-(2-cyclohexyloxynitrophenyl) methane sulfonamide,parecoxib, lumiracoxib, RS 57067, T-614, BMS-347070, JTE-522, S-2474,SVT-2016, CT-3, ABT-963, SC-58125, nimesulide, flosulide, NS-398,L-745337, RWJ-63556, L-784512, darbufelone, CS-502, LAS-34475,LAS-34555, S-33516, diclofenac, mefenamic acid, and SD-8381. In someembodiments, the COX inhibitor is selected from the group consisting ofibuprofen, naproxen, ketorolac, indomethacin, aspirin, naproxen,tolmetin, piroxicam, and meclofenamate. In some embodiments, the COXinhibitor is selected from the group consisting of SC-560, FR122047, P6,mofezolac, TFAP, flurbiprofen, ketoprofen, celecoxib, rofecoxib,meloxicam, piroxicam, deracoxib, parecoxib, valdecoxib, etoricoxib, achromene derivative, a chroman derivative,N-(2-cyclohexyloxynitrophenyl) methane sulfonamide, parecoxib,lumiracoxib, RS 57067, T-614, BMS-347070, JTE-522, S-2474, SVT-2016,CT-3, ABT-963, SC-58125, nimesulide, flosulide, NS-398, L-745337,RWJ-63556, L-784512, darbufelone, CS-502, LAS-34475, LAS-34555, S-33516,diclofenac, mefenamic acid, SD-8381, ibuprofen, naproxen, ketorolac,indomethacin, aspirin, naproxen, tolmetin, piroxicam, and meclofenamate.

In some embodiments, the anti-inflammatory agent is an NF-κB inhibitor.The NF-κB inhibitor can be any agent that inhibits the activity of theNF-κB pathway. In some embodiments, the NF-κB inhibitor is selected fromthe group consisting of an IKK complex inhibitor, an IκB degradationinhibitor, an NF-κB nuclear translocation inhibitor, a p65 acetylationinhibitor, an NF-κB DNA binding inhibitor, an NF-κB transactivationinhibitor, and a p53 induction inhibitor.

In some embodiments, the IKK complex inhibitor is selected from thegroup consisting of TPCA-1, NF-κB Activation Inhibitor VI (BOT-64),BMS-345541, amlexanox, SC-514 (GK-01140), IMD-0354, and IKK-16. In someembodiments, the IκB degradation inhibitor is selected from the groupconsisting of BAY-11-7082, MG-115, MG-132, lactacystin, epoxomicin,parthenolide, carfilzomib, and MLN-4924 (pevonedistat). In someembodiments, the NF-κB nuclear translocation inhibitor is selected fromthe group consisting of JSH-23 and rolipram. In some embodiments, thep65 acetylation inhibitor is selected from the group consisting ofgallic acid and anacardic acid. In some embodiments, the NF-κB DNAbinding inhibitor is selected from the group consisting of GYY-4137,p-XSC, CV-3988, and prostaglandin E2 (PGE2). In some embodiments, theNF-κB transactivation inhibitor is selected from the group consisting ofLY-294002, wortmannin, and mesalamine. In some embodiments, the p53induction inhibitor is selected from the group consisting of quinacrineand flavopiridol. In some embodiments, the NF-κB inhibitor is selectedfrom the group consisting of TPCA-1, NF-κB Activation Inhibitor VI(BOT-64), BMS-345541, amlexanox, SC-514 (GK-01140), IMD-0354, IKK-16,BAY-11-7082, MG-115, MG-132, lactacystin, epoxomicin, parthenolide,carfilzomib, MLN-4924 (pevonedistat), JSH-23 rolipram, gallic acid,anacardic acid, GYY-4137, p-XSC, CV-3988, prostaglandin E2 (PGE2),LY-294002, wortmannin, mesalamine, quinacrine, and flavopiridol.

In some embodiments, provided herein is a method of treatment orprevention of a cancer by administration of any masked cytokine orcomposition described herein in combination with an anti-cancertherapeutic protein. The anti-cancer therapeutic protein can be anytherapeutic protein capable of reducing cancer growth, interfering withcancer cell replication, directly or indirectly killing cancer cells,reducing metastasis, reducing tumor blood supply, or reducing cellsurvival. Exemplary anti-cancer therapeutic proteins may come in theform of an antibody or fragment thereof, an antibody derivative, abispecific antibody, a chimeric antigen receptor (CAR) T cell, a fusionprotein, or a bispecific T-cell engager (BiTE).

In some embodiments, provided herein is a method of treatment orprevention of an inflammatory or autoimmune disease by administration ofany masked cytokine or composition described herein. The term“inflammatory disease” refers to a disease caused by, resulting from, orresulting in, inflammation. The term “autoimmune disease” refers to adisease in which the subject's own immune system attacks its own cellsor tissues.

In some embodiments, the inflammatory or autoimmune disease is selectedfrom the group consisting of atherosclerosis, obesity, inflammatorybowel disease (IBD), rheumatoid arthritis, allergic encephalitis,psoriasis, atopic skin disease, osteoporosis, peritonitis, hepatitis,lupus, celiac disease, Sjogren's syndrome, polymyalgia rheumatica,multiple sclerosis (MS), ankylosing spondylitis, type 1 diabetesmellitus, alopecia areata, vasculitis, and temporal arteritis, graftversus host disease (GVHD), asthma, COPD, a paraneoplastic autoimmunedisease, cartilage inflammation, juvenile arthritis, juvenile rheumatoidarthritis, pauciarticular juvenile rheumatoid arthritis, polyarticularjuvenile rheumatoid arthritis, systemic onset juvenile rheumatoidarthritis, juvenile ankylosing spondylitis, juvenile enteropathicarthritis, juvenile reactive arthritis, juvenile Reiter's Syndrome, SEASyndrome (Seronegativity, Enthesopathy, Arthropathy Syndrome), juveniledermatomyositis, juvenile psoriatic arthritis, juvenile Scleroderma,juvenile systemic lupus erythematosus, juvenile vasculitis,pauciarticular rheumatoid arthritis, systemic onset rheumatoidarthritis, enteropathic arthritis, reactive arthritis, Reiter'sSyndrome, dermatomyositis, psoriatic arthritis, Scleroderma, vasculitis,myolitis, polymyolitis, dermatomyolitis, polyarteritis nodossa,Wegener's granulomatosis, arteritis, ploymyalgia rheumatica,sarcoidosis, Sclerosis, primary biliary Sclerosis, Sclerosingcholangitis, psoriasis, plaque psoriasis, guttate psoriasis, inversepsoriasis, pustular psoriasis, erythrodermic psoriasis, dermatitis,atopic dermatitis, atherosclerosis, Still's disease, Systemic LupusErythematosus (SLE), myasthenia gravis, Crohn's disease, ulcerativecolitis, celiac disease, rhinosinusitis, rhinosinusitis with polyps,eosinophilic esophogitis, eosinophilic bronchitis, Guillain-Barredisease, thyroiditis (e.g., Graves' disease), Addison's disease,Raynaud's phenomenon, autoimmune hepatitis, transplantation rejection,kidney damage, hepatitis C-induced vasculitis, and spontaneous loss ofpregnancy.

V. ARTICLES OF MANUFACTURE OR KITS

In another aspect, an article of manufacture or kit is provided whichcomprises any masked cytokine described herein. The article ofmanufacture or kit may further comprise instructions for use of thecytokines in the methods of the invention. Thus, in certain embodiments,the article of manufacture or kit comprises instructions for the use ofa masked cytokine in methods for treating or preventing a disorder(e.g., a cancer) in an individual comprising administering to theindividual an effective amount of a masked cytokine. For example, incertain embodiments, the article of manufacture or kit comprisesinstructions for the use of a masked IL-2 polypeptide in methods fortreating or preventing a disorder (e.g., a cancer) in an individualcomprising administering to the individual an effective amount of amasked IL-2 polypeptide. In certain embodiments, the individual is ahuman. In some embodiments, the individual has a disease selected fromthe group consisting of include leukemia, lymphoma, head and neckcancer, colorectal cancer, prostate cancer, pancreatic cancer, melanoma,breast cancer, neuroblastoma, lung cancer, ovarian cancer, osteosarcoma,bladder cancer, cervical cancer, liver cancer, kidney cancer, skincancer or testicular cancer.

The article of manufacture or kit may further comprise a container.Suitable containers include, for example, bottles, vials (e.g., dualchamber vials), syringes (such as single or dual chamber syringes), testtubes, and intravenous (IV) bags. The container may be formed from avariety of materials such as glass or plastic. The container holds theformulation. In some embodiments, the formulation is a lyophilizedformulation. In some embodiments, the formulation is a frozenformulation. In some embodiments, the formulation is a liquidformulation.

The article of manufacture or kit may further comprise a label or apackage insert, which is on or associated with the container, mayindicate directions for reconstitution and/or use of the formulation.The label or package insert may further indicate that the formulation isuseful or intended for subcutaneous, intravenous, or other modes ofadministration for treating or preventing a disorder (e.g., a cancer) inan individual. The container holding the formulation may be a single-usevial or a multi-use vial, which allows for repeat administrations of thereconstituted formulation. The article of manufacture or kit may furthercomprise a second container comprising a suitable diluent. The articleof manufacture or kit may further include other materials desirable froma commercial, therapeutic, and user standpoint, including other buffers,diluents, filters, needles, syringes, and package inserts withinstructions for use.

In a specific embodiment, the present invention provides kits for asingle dose-administration unit. Such kits comprise a container of anaqueous formulation of therapeutic cytokine, including both single ormulti-chambered pre-filled syringes. Exemplary pre-filled syringes areavailable from Vetter GmbH, Ravensburg, Germany.

The article of manufacture or kit herein optionally further comprises acontainer comprising a second medicament, wherein the masked cytokine isa first medicament, and which article or kit further comprisesinstructions on the label or package insert for treating the subjectwith the second medicament, in an effective amount.

In another embodiment, provided herein is an article of manufacture orkit comprising the formulations described herein for administration inan auto-injector device. An auto-injector can be described as aninjection device that upon activation, will deliver its contents withoutadditional necessary action from the patient or administrator. They areparticularly suited for self-medication of therapeutic formulations whenthe delivery rate must be constant and the time of delivery is greaterthan a few moments.

VI. Definitions

Unless defined otherwise, all terms of art, notations and othertechnical and scientific terms or terminology used herein are intendedto have the same meaning as is commonly understood by one of ordinaryskill in the art to which the claimed subject matter pertains. In somecases, terms with commonly understood meanings are defined herein forclarity and/or for ready reference, and the inclusion of suchdefinitions herein should not necessarily be construed to represent asubstantial difference over what is generally understood in the art.

It is to be understood that this invention is not limited to particularcompositions or biological systems, which can, of course, vary. It isalso to be understood that the terminology used herein is for thepurpose of describing particular embodiments only, and is not intendedto be limiting. As used in this specification and the appended claims,the singular forms “a,” “an,” and “the” include plural referents unlessthe content clearly dictates otherwise. Thus, for example, reference to“an IL-2 polypeptide” optionally includes a combination of two or moresuch polypeptides, and the like.

The term “about” as used herein refers to the usual error range for therespective value readily known to the skilled person in this technicalfield. Reference to “about” a value or parameter herein includes (anddescribes) embodiments that are directed to that value or parameter perse.

It is understood that aspects and embodiments of the invention describedherein include “comprising,” “consisting,” and “consisting essentiallyof” aspects and embodiments.

As used herein, the term “and/or” refers to any one of the items, anycombination of the items, or all of the items with which the term isassociated. For instance, the phrase “A, B, and/or C” is intended toencompass each of the following embodiments: A, B, and C; A, B, or C; Aor B; A or C; B or C; A and B; A and C; B and C; A and B or C; B and Aor C; C and A or B; A (alone); B (alone); and C (alone).

The term “antibody” includes polyclonal antibodies, monoclonalantibodies (including full length antibodies which have animmunoglobulin Fc region), antibody compositions with polyepitopicspecificity, multispecific antibodies (e.g., bispecific antibodies,diabodies, and single-chain molecules, as well as antibody fragments(e.g., Fab, F(ab′)2, and Fv). The term “immunoglobulin” (Ig) is usedinterchangeably with “antibody” herein.

The term “diabodies” refers to small antibody fragments with twoantigen-binding sites, which comprise a heavy chain variable (VH) domainconnected to a light chain variable (VL) domain in the same polypeptidechain (VH-VL).

The basic 4-chain antibody unit is a heterotetrameric glycoproteincomposed of two identical light (L) chains and two identical heavy (H)chains. An IgM antibody consists of 5 of the basic heterotetramer unitsalong with an additional polypeptide called a J chain, and contains 10antigen binding sites, while IgA antibodies comprise from 2-5 of thebasic 4-chain units which can polymerize to form polyvalent assemblagesin combination with the J chain. In the case of IgGs, the 4-chain unitis generally about 150,000 daltons. Each L chain is linked to an H chainby one covalent disulfide bond, while the two H chains are linked toeach other by one or more disulfide bonds depending on the H chainisotype. Each H and L chain also has regularly spaced intrachaindisulfide bridges. Each H chain has at the N-terminus, a variable domain(VH) followed by three constant domains (CH) for each of the α and γchains and four CH domains for μ and ε isotypes. Each L chain has at theN-terminus, a variable domain (VL) followed by a constant domain at itsother end. The VL is aligned with the VH and the CL is aligned with thefirst constant domain of the heavy chain (CH1). Particular amino acidresidues are believed to form an interface between the light chain andheavy chain variable domains. The pairing of a VH and VL together formsa single antigen-binding site. For the structure and properties of thedifferent classes of antibodies, see e.g., Basic and ClinicalImmunology, 8th Edition, Daniel P. Sties, Abba I. Terr and Tristram G.Parsolw (eds), Appleton & Lange, Norwalk, Conn., 1994, page 71 andChapter 6.

The L chain from any vertebrate species can be assigned to one of twoclearly distinct types, called kappa and lambda, based on the amino acidsequences of their constant domains. Depending on the amino acidsequence of the constant domain of their heavy chains (CH),immunoglobulins can be assigned to different classes or isotypes. Thereare five classes of immunoglobulins: IgA, IgD, IgE, IgG and IgM, havingheavy chains designated α, δ, ε, γ and μ, respectively. The γ and αclasses are further divided into subclasses on the basis of relativelyminor differences in the CH sequence and function, e.g., humans expressthe following subclasses: IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2. IgG1antibodies can exist in multiple polymorphic variants termed allotypes(reviewed in Jefferis and Lefranc 2009. mAbs Vol 1 Issue 4 1-7) any ofwhich are suitable for use in the invention. Common allotypic variantsin human populations are those designated by the letters a,f,n,z.

An “isolated” antibody is one that has been identified, separated and/orrecovered from a component of its production environment (e.g.,naturally or recombinantly). In some embodiments, the isolatedpolypeptide is free of association with all other components from itsproduction environment. Contaminant components of its productionenvironment, such as that resulting from recombinant transfected cells,are materials that would typically interfere with research, diagnosticor therapeutic uses for the antibody, and may include enzymes, hormones,and other proteinaceous or non-proteinaceous solutes. In someembodiments, the polypeptide is purified: (1) to greater than 95% byweight of antibody as determined by, for example, the Lowry method, andin some embodiments, to greater than 99% by weight; (1) to a degreesufficient to obtain at least 15 residues of N-terminal or internalamino acid sequence by use of a spinning cup sequenator, or (3) tohomogeneity by SDS-PAGE under non-reducing or reducing conditions usingCoomassie blue or silver stain. Isolated antibody includes the antibodyin situ within recombinant cells since at least one component of theantibody's natural environment will not be present. Ordinarily, however,an isolated polypeptide or antibody is prepared by at least onepurification step.

The term “monoclonal antibody” as used herein refers to an antibodyobtained from a population of substantially homogeneous antibodies,i.e., the individual antibodies comprising the population are identicalexcept for possible naturally occurring mutations and/orpost-translation modifications (e.g., isomerizations, amidations) thatmay be present in minor amounts. In some embodiments, monoclonalantibodies have a C-terminal cleavage at the heavy chain and/or lightchain. For example, 1, 2, 3, 4, or 5 amino acid residues are cleaved atthe C-terminus of heavy chain and/or light chain. In some embodiments,the C-terminal cleavage removes a C-terminal lysine from the heavychain. In some embodiments, monoclonal antibodies have an N-terminalcleavage at the heavy chain and/or light chain. For example, 1, 2, 3, 4,or 5 amino acid residues are cleaved at the N-terminus of heavy chainand/or light chain. In some embodiments truncated forms of monoclonalantibodies can be made by recombinant techniques. In some embodiments,monoclonal antibodies are highly specific, being directed against asingle antigenic site. In some embodiments, monoclonal antibodies arehighly specific, being directed against multiple antigenic sites (suchas a bispecific antibody or a multispecific antibody). The modifier“monoclonal” indicates the character of the antibody as being obtainedfrom a substantially homogeneous population of antibodies, and is not tobe construed as requiring production of the antibody by any particularmethod. For example, the monoclonal antibodies to be used in accordancewith the present invention may be made by a variety of techniques,including, for example, the hybridoma method, recombinant DNA methods,phage-display technologies, and technologies for producing human orhuman-like antibodies in animals that have parts or all of the humanimmunoglobulin loci or genes encoding human immunoglobulin sequences.

The terms “full-length antibody,” “intact antibody” or “whole antibody”are used interchangeably to refer to an antibody in its substantiallyintact form, as opposed to an antibody fragment. Specifically, wholeantibodies include those with heavy and light chains including an Fcregion. The constant domains may be native sequence constant domains(e.g., human native sequence constant domains) or amino acid sequencevariants thereof. In some cases, the intact antibody may have one ormore effector functions.

An “antibody fragment” comprises a portion of an intact antibody, suchas the antigen binding region and/or the variable region of the intactantibody, and/or the constant region of the intact antibody. Examples ofan antibody fragment include the Fc region of the antibody, a portion ofthe Fc region, or a portion of the antibody comprising the Fc region.Examples of antigen-binding antibody fragments include domain antibodies(dAbs), Fab, Fab′, F(ab′)2 and Fv fragments; diabodies; linearantibodies (see U.S. Pat. No. 5,641,870, Example 2; Zapata et al.,Protein Eng. 8(10): 1057-1062 [1995]); single-chain antibody molecules,and multispecific antibodies formed from antibody fragments. Singleheavy chain antibodies or single light chain antibodies can beengineered, or in the case of the heavy chain, can be isolated fromcamelids, shark, libraries or mice engineered to produce single heavychain molecules.

Papain digestion of antibodies produced two identical antigen-bindingfragments, called “Fab” fragments, and a residual “Fc” fragment, adesignation reflecting the ability to crystallize readily. The Fabfragment consists of an entire L chain along with the variable regiondomain of the H chain (VH), and the first constant domain of one heavychain (CH1). Each Fab fragment is monovalent with respect to antigenbinding, i.e., it has a single antigen-binding site. Pepsin treatment ofan antibody yields a single large F(ab′)2 fragment which roughlycorresponds to two disulfide linked Fab fragments having differentantigen-binding activity and is still capable of cross-linking antigen.Fab′ fragments differ from Fab fragments by having a few additionalresidues at the carboxy terminus of the CH1 domain including one or morecysteines from the antibody hinge region. Fab′-SH is the designationherein for Fab′ in which the cysteine residue(s) of the constant domainsbear a free thiol group. F(ab′)2 antibody fragments originally wereproduced as pairs of Fab′ fragments which have hinge cysteines betweenthem. Other chemical couplings of antibody fragments are also known. TheFc fragment comprises the carboxy-terminal portions of both H chainsheld together by disulfides. The effector functions of antibodies aredetermined by sequences and glycan in the Fc region, the region which isalso recognized by Fc receptors (FcR) found on certain types of cells.

The term “Fc region” herein is used to define a C-terminal region of animmunoglobulin heavy chain, including native-sequence Fc regions andvariant Fc regions. Although the boundaries of the Fc region of animmunoglobulin heavy chain might vary, the human IgG heavy-chain Fcregion is usually defined to stretch from an amino acid residue atposition Cys226, or from Pro230, to the carboxyl-terminus thereof.Suitable native-sequence Fc regions for use in the antibodies of theinvention include human IgG1, IgG2, IgG3 and IgG4.

The term “cytokine” refers to a secreted polypeptide or active fragmentor mutant thereof that modulates the activity of cells, particularlycells of the immune system. Examples of cytokines include, for instance,chemokines, interferons, interleukins, lymphokines, and tumor necrosisfactors. The term encompasses any cytokine protein, or a functionalfragment or variant thereof. The term encompasses any native cytokinefrom any vertebrate source, including mammals such as primates (e.g.,humans) and rodents (e.g., rats and mice), unless otherwise indicated.The term encompasses an unprocessed form of the cytokine as well as anyform of the cytokine that results from processing in a cell. The termalso encompasses naturally occurring variants of a cytokine. The termalso encompasses non-naturally occurring variants of a cytokine, such astruncations, deletions, forms where the cytokine is linked to anothermolecule, and variants caused by at least one amino acid change to theamino acid sequence (e.g., by substitution, addition, or deletion). Insome aspects, the variants or homologs have at least 90%, 95%, 96%, 97%,98%, 99% or 100% amino acid sequence identity across the whole sequenceor a portion of the sequence (e.g., a 50, 100, 125, or 150 or morecontinuous amino acid portion) compared to a naturally occurringcytokine polypeptide.

The term “IL-2” or “IL-2 polypeptide” as used herein refers to anyinterleukin-2 (IL-2) protein, or a functional fragment or variantthereof. The term encompasses any native IL-2 from any vertebratesource, including mammals such as primates (e.g., humans) and rodents(e.g., rats and mice), unless otherwise indicated. The term encompassesunprocessed IL-2 (e.g., a full length, precursor form of IL-2 thatconsists of amino acid residues 1-153) as well as any form of IL-2 thatresults from processing in the cell (e.g., a mature form of IL-2 thatconsists of amino acid residues 21-153). As such, the term encompasses aprotein encoded by the amino acid sequence of SEQ ID NO: 160, as well assequence variants thereof. The term also encompasses naturally occurringvariants of IL-2. The term also encompasses non-naturally occurringvariants of IL-2, such as truncations, deletions, forms where IL-2 islinked to another molecule, and variants caused by at least one aminoacid change to the amino acid sequence (e.g., by substitution, addition,or deletion). In some aspects, the variants or homologs have at least90%, 95%, 96%, 97%, 98%, 99% or 100% amino acid sequence identity acrossthe whole sequence or a portion of the sequence (e.g., a 50, 100, or 133continuous amino acid portion) compared to a naturally occurring IL-2polypeptide, such as an IL-2 polypeptide encoded by the amino acidsequence of SEQ ID NO: 159 or 160. As such, the term “IL-2” or “IL-2polypeptide” includes an IL-2 protein comprising the amino acid sequenceof any one of SEQ ID NOs: 1-8, 159, 160, 230, 243-251, 260, 775-792, and813-822, including variants thereof, such as variants created by one ormore amino acid substitutions to the amino acid sequence of any one ofSEQ ID NOs: 1-8, 159, 160, 230, 243-251, 260, 775-792, and 813-822.

The term “IL-15” or “IL-15 polypeptide” as used herein refers to anyinterleukin-15 (IL-15) protein, or a functional fragment or variantthereof. The term encompasses any native IL-15 from any vertebratesource, including mammals such as primates (e.g., humans) and rodents(e.g., rats and mice), unless otherwise indicated. The term encompassesunprocessed IL-15 (e.g., a full length, precursor form of IL-15 thatconsists of amino acid residues 1-162) as well as any form of IL-15 thatresults from processing in the cell (e.g., a mature form of IL-15 thatconsists of amino acid residues 49-162). As such, the term encompasses aprotein encoded by the amino acid sequence of SEQ ID NO: 167, as well assequence variants thereof. The term also encompasses naturally occurringvariants of IL-15. The term also encompasses non-naturally occurringvariants of IL-15, such as truncations, deletions, forms where IL-15 islinked to another molecule, and variants caused by at least one aminoacid change to the amino acid sequence (e.g., by substitution, addition,or deletion). In some aspects, the variants or homologs have at least90%, 95%, 96%, 97%, 98%, 99% or 100% amino acid sequence identity acrossthe whole sequence or a portion of the sequence (e.g., a 50, 100, or 114continuous amino acid portion) compared to a naturally occurring IL-15polypeptide, such as an IL-15 polypeptide encoded by the amino acidsequence of SEQ ID NO: 166 or 167. As such, the term “IL-15” or “IL-15polypeptide” includes an IL-15 protein comprising the amino acidsequence of SEQ ID NO: 166 or 167, including variants thereof, such asvariants created by one or more amino acid substitutions to the aminoacid sequence of SEQ ID NO: 166 or 167.

“Functional fragments” of a cytokine comprise a portion of a full lengthcytokine protein which retains or has modified cytokine receptor bindingcapability (e.g., within at least 50%, 80%, 90%, 95%, 96%, 97%, 98%, 99%or 100% activity compared to the full length cytokine protein). The fulllength cytokine protein can be a full length cytokine protein of awildtype cytokine protein, or it can be a full length cytokine proteinof a modified variant of a cytokine protein, such as a full lengthcytokine that has been modified by one or more amino acid substitutions.Cytokine receptor binding capability can be shown, for example, by thecapability of a cytokine to bind to the cytokine's cognate receptor or acomponent thereof (e.g., one or more chain(s) of a heterotrimericreceptor complex). As used herein, “full length” can refer to the fulllength of a cytokine in its unprocessed (i.e., precursor) form or it'sprocessed (i.e., mature) form. The term also encompasses a portion of afull length protein which retains or has modified cytokine receptorbinding capability (e.g., within at least 50%, 80%, 90%, 95%, 96%, 97%,98%, 99% or 100% activity compared to the full length cytokine protein)and has been further modified to include one or more modifications tothe amino acid sequence, such as one or more amino acid deletions,additions, or substitutions. Thus, a functional fragment of a cytokinenot only encompasses a portion of a full length cytokine protein, but italso encompasses a variant of a portion of a full length cytokineprotein. For instance, a functional fragment of an IL-2 polypeptidecomprises a portion of a full length IL-2 protein which retains or hasmodified IL-2R binding capability (e.g., within at least 50%, 80%, 90%,95%, 96%, 97%, 98%, 99% or 100% activity compared to full lengthwildtype IL-2). IL-2R binding capability can be shown, for example, bythe capability to bind to the IL-2Rα chain, the IL-2Rβ chain, and/or theIL-2Rγ chain of the IL-2R, either individually or in combination withone another. A functional fragment of IL-2 includes, for example, anIL-2 protein that comprises amino acid residues 21-153 of the fulllength IL-2 sequence of SEQ ID NO: 159, as well as variants thereof,such as variants that include one or more substitutions to the aminoacid sequence. As such, a functional fragment of IL-2 includes, forexample, an IL-2 protein comprising the amino acid sequence of any oneof SEQ ID NOs: 1-8, 160, 230, 243-251, 260, 775-792, and 813-822. Afunctional fragment of IL-15 includes, for example, an IL-15 proteincomprising the amino acid sequence of SEQ ID NO: 167.

The term “activatable” as used herein to describe any cytokine orfunctional fragment thereof means a cytokine or functional fragmentthereof has been modified to comprise a masking moiety, and, in someembodiments, other components, that allow for activation of the cytokineor functional fragment thereof in a preferred environment. For example,a cytokine or functional fragment thereof that has been modified tocomprise an masking moiety for activation in a preferred environment maybe referred to herein as an “activatable cytokine,” or “maskedcytokine,” or “activatable masked cytokine.” As such, the term “maskedcytokine” includes any cytokine or functional fragment thereof that hasbeen modified to comprise a masking moiety, and, in some embodiments,other components, such as a cleavable peptide, that allow for activationof the cytokine or functional fragment thereof in a preferredenvironment.

The term “masking moiety” as used herein refers to a peptide capable ofbinding to, or otherwise exhibiting an affinity for, a cytokine orfunctional fragment thereof such that the masking moiety blocks,occludes, inhibits (e.g., decreases) or otherwise prevents (e.g., masks)the activity or binding of the cytokine or functional fragment thereofto its cognate receptor or protein. In some embodiments, the maskingmoiety is a cytokine receptor, or a subunit or functional fragmentthereof.

The term “cytokine receptor” as used herein refers to any receptorwithin the art that binds to one or more cytokine(s) including, but notlimited to, receptors of IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8,IL-9, IL-10, IL-11, IL-12, IL-13, IL-14, IL-15, IL-16, IL-17, IL-18,IL-19, IL-20, IL-21, IL-22, IL-23, IL-24, IL-25, IL-26, IL-27, IL-28A,IL-28B, IL-29, IL-30, IL-31, IL-32, IL-33, IL-34, IL-35, IL-36, IL-37,granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophagecolony-stimulating factor (M-CSF), tumor necrosis factor alpha (TNF-α),transforming growth factor beta (TGF-β), IFN-γ (gamma), CD252, CD154,CD178, CD70, CD153, 4-1BB-L, TRAIL, RANKL, APO3L, CD256, CD257, CD258,TL1, AITRL, EDA1, interferon (IFN)-α (alpha), IFN-β (beta), IFN-γ(gamma), growth hormone (GH), erythropoietin (EPO), prolactin (PRL),leukemia inhibitory factor (LIF), oncostatin (OSM), and thrombopoietin(TPO). Some cytokine receptors function, in whole or in part, asheteromeric complexes of more than one subunit, or as homomericcomplexes. The term also encompasses subunits of cytokine receptors thatare capable of binding to one or more cytokine(s) either individually orwhen in complex with one or more other cytokine receptor subunits (e.g.,as a heteromeric or homomeric complex). As such, reference to a“cytokine receptor” that is a heteromeric complex of three subunits, forexample, includes reference to the heteromeric complex comprising allthree subunits, as well as reference to each subunit individually or invarious combinations with one another. Non-limiting examples of cytokinereceptors include CXCR1, CXCR2, CXCR3, CXCR4, CXCR5, CXCR6, CXCR7, CCR1,CCR2, CCR3, CCR4, CCR5, CCR6, CCR7, CCR8, CCR9, CCR10, CCR11, XCR1,CX3CR1, IL-1RAP, IL-1RAPL1, IL-1RAPL2, IL-1RL1, IL-1RL2, IL-1R1, IL-1R2,IL-2R, IL-2Rα, IL-2R13, IL-2Rγ, IL-3Rα, IL-4R, IL-5Rα, IL-6R, IL-6ST,IL-7R, IL-9R, IL-10Rα, IL-10R13, IL-11Rα, IL-12R131, IL-12R132,IL-13Rα1, IL-13Rα2, IL-15Rα, IL-17RA, IL-17RB, IL-17RC, IL-17RD,IL-17RE, IL-18RAP, IL-18R1, IL-20Rα, IL-20R13, IL-21R, IL-22Rα1,IL-22Rα2, IL-23R, IL-27Rα, IL-28Rα, IL-31RA, IFNAR1, IFNAR2, IFNGR1,IFNGR2, IFNLR1, GMRa (CD116), CD131, GHR, PRLR, EPOR, LIFR (CD118),OSMRI3, TPO-R (CD110), CSF-1R, EDAR, TNFRSF1A, TNFRSF1B, LTBR, TNFRSF4,CD40, FAS, TNFRSF6B, CD27, TNFRSF8, TNFRSF9, TNFRSF10A, TNFRSF10B,TNFRSF10C, TNFRSF10D, TNFRSF11A, TNFRSF11B, TNFRSF12A, TNFRSF13B,TNFRSF13C, TNFRSF14, NGFR, TNFRSF17, TNFRSF18, TNFRSF19, RELT, TNFRSF21,TNFRSF25, and EDA2R.

The term “IL-2R” or “IL-2 receptor” or “IL-2 cytokine receptor” as usedherein refers to the high-affinity IL-2 receptor complex that comprisesthree separate and non-covalently linked chains: the IL-2Rα chain (alsoreferred to as CD25), the IL-2Rβ chain (also referred to as CD122), andthe IL-2Rγ chain (also referred to as CD132). IL-2 is capable of bindingto the IL-2Rα chain. IL-2 is also capable of binding to the IL-2Rα chainin combination with the IL-2Rβ chain. IL-2 is also capable of binding tothe IL-2Rα chain in combination with the IL-2Rβ and IL-2Rγ chains withhighest affinity. In some cases, the term also encompasses the IL-2Rαchain, the IL-2Rβ chain, or the IL-2Rγ chain, or combinations thereof.

The term “IL-15R” or “IL-15 receptor” or “IL-15 cytokine receptor” asused herein refers to the high-affinity IL-15 receptor complex thatcomprises three separate and non-covalently linked chains: the IL-15Rαchain, the IL-2Rβ chain, and the IL-2Rγ chain. IL-15 is capable ofbinding to the IL-15Rα chain, to the heterodimer of the IL-2Rβ chain andthe IL-2Rγ chain, and to the IL-15Rα chain in combination with theIL-2Rβ chain and the IL-2Rγ chain. In some cases, the term alsoencompasses the IL-15Rα chain, the IL-2Rβ chain, or the IL-2Rγ chain, orcombinations thereof.

The term “half-life extension domain” refers to a domain that is linkedto a target component (e.g., a cytokine or functional fragment thereof,or a masking moiety) for the purpose of extending the half-life of thetarget component in serum. The term “half-life extension domain”encompasses, for example, antibodies, antibody fragments, bispecificantibodies, albumin, binding proteins (e.g., albumin-binding proteinsand IgG-binding proteins), polyamino acid sequences, and antibodyderivatives (e.g., scFvs, scFcs, dual-variable-domains, and antibodyderivatives based on the CrossMab approach).

“Percent (%) amino acid sequence identity” with respect to a referencepolypeptide sequence is defined as the percentage of amino acid residuesin a candidate sequence that are identical with the amino acid residuesin the reference polypeptide sequence, after aligning the sequences andintroducing gaps, if necessary, to achieve the maximum percent sequenceidentity, and not considering any conservative substitutions as part ofthe sequence identity. Alignment for purposes of determining percentamino acid sequence identity can be achieved in various ways that arewithin the skill in the art, for instance, using publicly availablecomputer software such as BLAST, BLAST-2, ALIGN or Megalign (DNASTAR)software. Those skilled in the art can determine appropriate parametersfor aligning sequences, including any algorithms needed to achievemaximal alignment over the full length of the sequences being compared.For example, the % amino acid sequence identity of a given amino acidsequence A to, with, or against a given amino acid sequence B (which canalternatively be phrased as a given amino acid sequence A that has orcomprises a certain % amino acid sequence identity to, with, or againsta given amino acid sequence B) is calculated as follows:

100 times the fraction X/Y

where X is the number of amino acid residues scored as identical matchesby the sequence in that program's alignment of A and B, and where Y isthe total number of amino acid residues in B. It will be appreciatedthat where the length of amino acid sequence A is not equal to thelength of amino acid sequence B, the % amino acid sequence identity of Ato B will not equal the % amino acid sequence identity of B to A.

Antibody “effector functions” refer to those biological activitiesattributable to the Fc region (a native sequence Fc region or amino acidsequence variant Fc region) of an antibody, and vary with the antibodyisotype. Examples of antibody effector functions include: C1 q bindingand complement dependent cytotoxicity; Fc receptor binding;antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; downregulation of cell surface receptors (e.g., B cell receptors); and Bcell activation.

“Binding affinity” as used herein refers to the strength of thenon-covalent interactions between a single binding site of a molecule(e.g., a cytokine) and its binding partner (e.g., a cytokine receptor).In some embodiments, the affinity of a binding protein (e.g., acytokine) can generally be represented by a dissociation constant (Kd).Affinity can be measured by common methods known in the art, includingthose described herein.

An “isolated” nucleic acid molecule encoding the cytokine polypeptidesdescribed herein is a nucleic acid molecule that is identified andseparated from at least one contaminant nucleic acid molecule with whichit is ordinarily associated in the environment in which it was produced.In some embodiments, the isolated nucleic acid is free of associationwith all components associated with the production environment. Theisolated nucleic acid molecules encoding the polypeptides and cytokinepolypeptides herein is in a form other than in the form or setting inwhich it is found in nature. Isolated nucleic acid molecules thereforeare distinguished from nucleic acid encoding the polypeptides andcytokine polypeptides herein existing naturally in cells.

The term “pharmaceutical formulation” refers to a preparation that is insuch form as to permit the biological activity of the active ingredientto be effective, and that contains no additional components that areunacceptably toxic to a subject to which the formulation would beadministered. Such formulations are sterile.

“Carriers” as used herein include pharmaceutically acceptable carriers,excipients, or stabilizers that are nontoxic to the cell or mammal beingexposed thereto at the dosages and concentrations employed. Often thephysiologically acceptable carrier is an aqueous pH buffered solution.Examples of physiologically acceptable carriers include buffers such asphosphate, citrate, and other organic acids; antioxidants includingascorbic acid; low molecular weight (less than about 10 residues)polypeptide; proteins, such as serum albumin, gelatin, orimmunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone;amino acids such as glycine, glutamine, asparagine, arginine or lysine;monosaccharides, disaccharides, and other carbohydrates includingglucose, mannose, or dextrins; chelating agents such as EDTA; sugaralcohols such as mannitol or sorbitol; salt-forming counterions such assodium; and/or nonionic surfactants such as TWEEN™, polyethylene glycol(PEG), and PLURONICS™.

As used herein, the term “treatment” refers to clinical interventiondesigned to alter the natural course of the individual or cell beingtreated during the course of clinical pathology. Desirable effects oftreatment include decreasing the rate of disease progression,ameliorating or palliating the disease state, and remission or improvedprognosis. An individual is successfully “treated”, for example, if oneor more symptoms associated with a disorder (e.g., a neoplastic disease)are mitigated or eliminated. For example, an individual is successfully“treated” if treatment results in increasing the quality of life ofthose suffering from a disease, decreasing the dose of other medicationsrequired for treating the disease, reducing the frequency of recurrenceof the disease, lessening severity of the disease, delaying thedevelopment or progression of the disease, and/or prolonging survival ofindividuals.

As used herein, “in conjunction with” or “in combination with” refers toadministration of one treatment modality in addition to anothertreatment modality. As such, “in conjunction with” or “in combinationwith” refers to administration of one treatment modality before, duringor after administration of the other treatment modality to theindividual.

As used herein, the term “prevention” includes providing prophylaxiswith respect to occurrence or recurrence of a disease in an individual.An individual may be predisposed to, susceptible to a disorder, or atrisk of developing a disorder, but has not yet been diagnosed with thedisorder. In some embodiments, masked cytokines described herein areused to delay development of a disorder.

As used herein, an individual “at risk” of developing a disorder may ormay not have detectable disease or symptoms of disease, and may or maynot have displayed detectable disease or symptoms of disease prior tothe treatment methods described herein. “At risk” denotes that anindividual has one or more risk factors, which are measurable parametersthat correlate with development of the disease, as known in the art. Anindividual having one or more of these risk factors has a higherprobability of developing the disorder than an individual without one ormore of these risk factors.

An “effective amount” refers to at least an amount effective, at dosagesand for periods of time necessary, to achieve the desired or indicatedeffect, including a therapeutic or prophylactic result. An effectiveamount can be provided in one or more administrations. A“therapeutically effective amount” is at least the minimum concentrationrequired to effect a measurable improvement of a particular disorder. Atherapeutically effective amount herein may vary according to factorssuch as the disease state, age, sex, and weight of the patient, and theability of the antibody to elicit a desired response in the individual.A therapeutically effective amount may also be one in which any toxic ordetrimental effects of the masked cytokine are outweighed by thetherapeutically beneficial effects. A “prophylactically effectiveamount” refers to an amount effective, at the dosages and for periods oftime necessary, to achieve the desired prophylactic result. Typically,but not necessarily, since a prophylactic dose is used in subjects priorto or at the earlier stage of disease, the prophylactically effectiveamount can be less than the therapeutically effective amount.

“Chronic” administration refers to administration of the medicament(s)in a continuous as opposed to acute mode, so as to main the initialtherapeutic effect (activity) for an extended period of time.“Intermittent” administration is treatment that is not consecutivelydone without interruption, but rather is cyclic in nature.

As used herein, an “individual” or a “subject” is a mammal A “mammal”for purposes of treatment includes humans, domestic and farm animals,and zoo, sports, or pet animals, such as dogs, horses, rabbits, cattle,pigs, hamsters, gerbils, mice, ferrets, rats, cats, etc. In someembodiments, the individual or subject is human.

VII. EXEMPLARY EMBODIMENTS

Among the provided embodiments are:

1. A masked cytokine comprising:

a) a masking moiety; and

b) a cytokine or functional fragment thereof,

wherein the masking moiety is linked to the cytokine or functionalfragment thereof via a first linker.

2. The masked cytokine of embodiment 1, further comprising a half-lifeextension domain that is linked to either the masking moiety or thecytokine or functional fragment thereof.

3. The masked cytokine of embodiment 2, wherein the half-life extensiondomain is linked to either the masking moiety or the cytokine orfunctional fragment thereof via a second linker.

4. The masked cytokine of embodiment 2 or embodiment 3, wherein:

i) the masked cytokine comprises in an N to C-terminal or in a C toN-terminal direction: a) the masking moiety; b) the first linker; c) thecytokine or functional fragment thereof; and d) the half-life extensiondomain;

ii) the masked cytokine comprises in an N to C-terminal or in a C toN-terminal direction: a) the masking moiety; b) the first linker; c) thecytokine or functional fragment thereof; d) the second linker and e) thehalf-life extension domain;

iii) the masked cytokine comprises in an N to C-terminal or in a C toN-terminal direction: a) the cytokine or functional fragment thereof; b)the first linker; c) the masking moiety; and d) the half-life extensiondomain; or

iv) the masked cytokine comprises in an N to C-terminal or in a C toN-terminal direction: a) the cytokine or functional fragment thereof; b)the first linker; c) the masking moiety; d) the second linker; and e)the half-life extension domain.

5. The masked cytokine of any one of embodiments 1-4, wherein thecytokine or functional fragment thereof is an IL-2 polypeptide orfunctional fragment thereof.

6. The masked cytokine of embodiment 5, wherein the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 1-8, 160, 230, 243-251, 260,775-792, and 813-822.

7. The masked cytokine of embodiment 5, wherein the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byintroducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatreduces the affinity of the IL-2 polypeptide or functional fragmentthereof for CD25 (IL-2Rα).

8. The masked cytokine of embodiment 7, wherein the amino acid sequenceis produced by introducing one or more of the following amino acidsubstitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: R38A, F42A, F42K, F42E, K43A, Y45A, Y45N, Y45R,E62A, E62R, E62S, and L72G.

9. The masked cytokine of embodiment 5, wherein the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byintroducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatincreases the affinity of the IL-2 polypeptide or functional fragmentthereof for IL-2Rβ or IL-2Rγ.

10. The masked cytokine of embodiment 9, wherein the amino acid sequenceis produced by introducing one or more of the following amino acidsubstitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: H161, L18C, D20A, D20L, D20F, N29L, L80F, R81D,L85V, I86V, and I92F.

11. The masked cytokine of embodiment 7 or embodiment 8, wherein theamino acid sequence is produced by further introducing one or more aminoacid substitutions that increase the affinity of the IL-2 polypeptide orfunctional fragment thereof for IL-2Rβ or IL-2Rγ.

12. The masked cytokine of embodiment 11, wherein the one or more aminoacid substitutions that increase the affinity of the IL-2 polypeptide orfunctional fragment thereof for IL-2Rβ or IL-2Rγ is selected from thegroup consisting of H161, L18C, D20A, D20L, D20F, N29L, L80F, R81D,L85V, I86V, and I92F.

13. The masked cytokine of embodiment 5, wherein the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byintroducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatstabilizes the IL-2 polypeptide or functional fragment thereof.

14. The masked cytokine of embodiment 13, wherein the amino acidsequence is produced by introducing one of the following amino acidsubstitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: C125S, C125A, and C125G.

15. The masked cytokine of any one of embodiments 7-12, wherein theamino acid sequence is produced by further introducing one or more aminoacid substitutions that stabilize the IL-2 polypeptide or functionalfragment thereof.

16. The masked cytokine of embodiment 15, wherein the one or more aminoacid substitutions that stabilize the IL-2 polypeptide or functionalfragment thereof is the amino acid substitution C125S, C125A, or C125G.

17. The masked cytokine of any one of embodiments 5-16, wherein themasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 9, 10, 161-165, 187-218, 221-229, 231, 261,826 and 827.

18. The masked cytokine of any one of embodiments 1-4, wherein thecytokine or functional fragment thereof is an IL-15 polypeptide orfunctional fragment thereof.

19. The masked cytokine of embodiment 18, wherein the IL-15 polypeptideor functional fragment thereof comprises the amino acid sequence of SEQID NO: 167.

20. The masked cytokine of embodiment 18 or embodiment 19, wherein themasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 219-229, 232-234, 261, and823-827.

21. The masked cytokine of embodiment 18 or embodiment 19, wherein themasking moiety comprises an amino acid sequence produced by introducingone or more of the following amino acid substitutions into the aminoacid sequence of any one of SEQ ID NOs: 232-234, and 823-825: R24A,R26A, K34A, 540A, L42A, and P67A.

22. The masked cytokine of any one of embodiments 2-21, wherein thehalf-life extension domain is an antibody or fragment thereof.

23. The masked cytokine of embodiment 22, wherein the antibody orfragment thereof comprises either a heavy chain polypeptide or a lightchain polypeptide.

24. The masked cytokine of embodiment 23, wherein the heavy chainpolypeptide comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 158, 168, and 169.

25. The masked cytokine of embodiment 23, wherein the heavy chainpolypeptide comprises one or more amino acid substitutions alteringeffector function.

26. The masked cytokine of embodiment 25, wherein the heavy chainpolypeptide:

a) is an IgG1 heavy chain polypeptide and comprises the amino acidsubstitution(s):

-   -   i) N297A, N297G, or N297Q;    -   ii) L234A and L235A;    -   iii) C220S, C226S, C229S, and P238S;    -   iv) C226S, C229S, E233P, L234V, and L235A;    -   v) L234F, L235E, and P331S;    -   vi) S267E and L328F;    -   vii) D265A;    -   viii) L234A, L235A, and P329G;

b) is an IgG2 heavy chain polypeptide and comprises the amino acidsubstitution(s):

-   -   i) V234A and G237A;    -   ii) H268Q, V309L, A330S, and A331S; or    -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or

e) is an IgG4 heavy chain polypeptide and comprises the amino acidsubstitution(s):

-   -   i) L235A, G237A, and E318A;    -   ii) S228P, L234A, and L235A;    -   iii) H268Q, V309L, A330S, and P331S; or    -   iv) S228P and L235A, numbered according to the Kabat EU        numbering system.

27. The masked cytokine of embodiment 25, wherein the heavy chainpolypeptide comprises one or more amino acid substitutions enhancingeffector function.

28. The masked cytokine of embodiment 27, wherein the heavy chainpolypeptide is an IgG1 heavy chain polypeptide and comprises the aminoacid substitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;    -   m) K290E, S298G, and T299A;    -   n) K290E, S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;    -   p) K290N, S298G, T299A, and K326E;    -   q) K334V;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and I332N;    -   av) S239D and I332Q;    -   aw) S239E and I332D;    -   ax) S239E and I332N;    -   ay) S239E and I332Q;    -   az) S239N and I332D;    -   ba) S239N and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, I332E, and either S239D or S239N;    -   br) A330L, I332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, 1332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, 1332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;    -   ch) E318R;    -   ci) S324D, 53241 or S324V;    -   cj) K326I or K326T;    -   ck) T335D, T335R, or T335Y;    -   cl) V240I and V266I;    -   cm) S239D, A330Y, 1332E, and L234I;    -   cn) S239D, A330Y, 1332E, and L235D;    -   co) S239D, A330Y, 1332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

29. The masked cytokine of embodiment 23, wherein the light chainpolypeptide comprises the amino acid sequence of SEQ ID NO: 157 or 170.

30. The masked cytokine of embodiment 22, wherein the antibody orfragment thereof is a Fragment crystallizable domain (Fc domain) orfragment thereof.

31. The masked cytokine of embodiment 30, wherein the Fc domain orfragment thereof comprises one or more amino acid substitutions alteringeffector function.

32. The masked cytokine of embodiment 31, wherein the Fc domain orfunctional fragment thereof:

a) is an IgG1 Fc domain or functional fragment thereof and comprises theamino acid substitution(s):

-   -   i) N297A, N297G, or N297Q;    -   ii) L234A and L235A;    -   iii) C220S, C226S, C229S, and P238S;    -   iv) C226S, C229S, E233P, L234V, and L235A;    -   v) L234F, L235E, and P331S;    -   vi) S267E and L328F;    -   vii) D265A;    -   viii) L234A, L235A, and P329G;

b) is an IgG2 Fc domain or functional fragment thereof and comprises theamino acid substitution(s):

-   -   i) V234A and G237A;    -   ii) H268Q, V309L, A330S, and A331S; or    -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or

e) is an IgG4 Fc domain or functional fragment thereof and comprises theamino acid substitution(s):

-   -   i) L235A, G237A, and E318A;    -   ii) S228P, L234A, and L235A;    -   iii) H268Q, V309L, A330S, and P331S; or    -   iv) S228P and L235A, numbered according to the Kabat EU        numbering system.

33. The masked cytokine of embodiment 31, wherein the Fc domain orfunctional fragment thereof comprises one or more amino acidsubstitutions enhancing effector function.

34. The masked cytokine of embodiment 33, wherein the Fc domain orfunctional fragment thereof is an IgG1 Fc domain or functional fragmentthereof and comprises the amino acid substitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;    -   m) K290E, S298G, and T299A;    -   n) K290E, S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;    -   p) K290N, S298G, T299A, and K326E;    -   q) K334V;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and I332N;    -   av) S239D and I332Q;    -   aw) S239E and I332D;    -   ax) S239E and I332N;    -   ay) S239E and I332Q;    -   az) S239N and I332D;    -   ba) S239N and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, I332E, and either S239D or S239N;    -   br) A330L, I332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;    -   ch) E318R;    -   ci) S324D, S324I or S324V;    -   cj) K326I or K326T;    -   ck) T335D, T335R, or T335Y;    -   cl) V240I and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

35. The masked cytokine of any one of embodiments 30-32, wherein the Fcdomain or fragment thereof comprises the amino acid sequence of SEQ IDNO: 154.

36. The masked cytokine of any one of embodiments 2-21, wherein thehalf-life extension domain is an albumin polypeptide or fragmentthereof.

37. The masked cytokine of embodiment 36, wherein the albuminpolypeptide or fragment thereof comprises the amino acid sequence of SEQID NO: 171.

38. The masked cytokine of any one of embodiments 2-21, wherein thehalf-life extension domain is an albumin-binding protein or fragmentthereof.

39. The masked cytokine of embodiment 38, wherein the albumin-bindingprotein or fragment thereof comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 172-174 and 252-259.

40. The masked cytokine of any one of embodiments 2-21, wherein thehalf-life extension domain is an IgG-binding protein or fragmentthereof.

41. The masked cytokine of embodiment 40, wherein the IgG bindingprotein or functional fragment thereof comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 175-186.

42. The masked cytokine of any one of embodiments 2-21, wherein thehalf-life extension domain is a polyamino acid sequence.

43. The masked cytokine of embodiment 42, wherein the polyamino acidsequence is a PAS polypeptide or an XTEN polypeptide.

44. The masked cytokine of embodiment 43, wherein the PAS polypeptidecomprises at least 25, at least 50, at least 100, at least 150, at least200, at least 250, at least 300, at least 400, at least 500, at least600, at least 700, at least 800, at least 900, at least 1000, at least1100, at least 1200, at least 1300, at least 1500, at least 2000, atleast 2500, or at least 3000 amino acid residues, wherein each aminoacid residue is either a proline or an alanine residue.

45. The masked cytokine of embodiment 43, wherein the PAS polypeptidecomprises at least 25, at least 50, at least 100, at least 150, at least200, at least 250, at least 300, at least 400, at least 500, at least600, at least 700, at least 800, at least 900, at least 1000, at least1100, at least 1200, at least 1300, at least 1500, at least 2000, atleast 2500, or at least 3000 amino acid residues, wherein each aminoacid residue is selected from the group consisting of a proline, analanine, and a serine residue.

46. The masked cytokine of embodiment 43, wherein the XTEN polypeptidecomprises an amino acid sequence of about 25 to about 500, about 200 toabout 1000, about 500 to about 1500, about 1000 to about 2000, or about1500 to about 3000 amino acid residues, wherein at least about 70%, 75%,80%, or 85% of the amino acid sequence consists of non-overlappingsequence motifs where each of the motifs has 5 to 100 amino acidresidues, 5 to 50 amino acids residues, or 9 to 36 amino acid residues,and wherein at least 90%, at least 91%, at least 92%, at least 93%, atleast 94%, at least 95%, at least 96%, at least 97%, at least 98%, atleast 99%, or 100% of each of the motifs consists of four, five, or sixtypes of amino acid residues selected from the group consisting ofglycine (G), alanine (A), serine (S), threonine (T), glutamate (E) andproline (P), and wherein the content of any one amino acid type in thefull-length XTEN polypeptide does not exceed about 40%, about 35%, about30%, about 25%, about 15%, about 10%, or about 8%.

47. The masked cytokine of any one of embodiments 1-46, wherein themasked cytokine further comprises one or more PEG polymer chainsattached to the masked cytokine.

48. The masked cytokine of embodiment 47, wherein the one or more PEGpolymer chains are attached to the cytokine or functional fragmentthereof and/or the half-life extension domain.

49. The masked cytokine of any one of embodiments 1-48, wherein themasked cytokine is modified, or is further modified, by altering theamino acid sequence of the masked cytokine such that one or moreadditional N-linked and/or O-linked glycosylation sites are created.

50. The masked cytokine of embodiment 49, wherein the masked cytokine ismodified, or is further modified, by altering the amino acid sequence ofthe masked cytokine such that one or more additional asparagine-X-serine(N—X—S) and/or asparagine-X-threonine (N-X-T) tripeptide sequence(s)is/are introduced into the amino acid sequence of the masked cytokine,wherein X is any amino acid except proline.

51. The masked cytokine of embodiment 49 or embodiment 50, wherein themasked cytokine is modified, or is further modified, by altering theamino acid sequence of the masked cytokine such that one or moreadditional serine or threonine residues is/are introduced into the aminoacid sequence of the masked cytokine.

52. The masked cytokine of any one of embodiments 1-51, wherein thefirst linker comprises a first cleavable peptide.

53. The masked cytokine of any one of embodiments 1-52, where the firstlinker comprises a first N-terminal spacer domain and/or a firstC-terminal spacer domain.

54. The masked cytokine of embodiment 53, wherein the first linkercomprises:

-   -   a) the first N-terminal spacer domain, the first cleavable        peptide, and the first C-terminal spacer domain;    -   b) the first N-terminal spacer domain and the first cleavable        peptide;    -   c) the first N-terminal spacer domain and the first C-terminal        spacer domain;    -   d) the first cleavable peptide and the first C-terminal spacer        domain;    -   e) the first N-terminal spacer domain; or    -   f) the first C-terminal spacer domain.

55. The masked cytokine of embodiment 53 or embodiment 54, wherein thefirst cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

56. The masked cytokine of any one of embodiments 53-55, wherein thefirst N-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

57. The masked cytokine of any one of embodiments 53-55, wherein thefirst C-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

58. The masked cytokine of embodiment 53 or embodiment 54, wherein thefirst cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

59. The masked cytokine of embodiment 58, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

60. The masked cytokine of any one of embodiments 1-59, wherein thefirst linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812.

61. The masked cytokine of any one of embodiments 3-60, wherein thesecond linker comprises a second cleavable peptide.

62. The masked cytokine of any one of embodiments 3-61, wherein thesecond linker comprises a second N-terminal spacer domain and/or asecond C-terminal spacer domain.

63. The masked cytokine of embodiment 62, wherein the second linkercomprises:

-   -   a) the second N-terminal spacer domain, the second cleavable        peptide, and second first C-terminal spacer domain;    -   b) the second N-terminal spacer domain and the second cleavable        peptide;    -   c) the second N-terminal spacer domain and the second C-terminal        spacer domain;    -   d) the second cleavable peptide and the second C-terminal spacer        domain;    -   e) the second N-terminal spacer domain; or    -   f) the second C-terminal spacer domain.

64. The masked cytokine of any one of embodiments 61-63, wherein thesecond cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

65. The masked cytokine of any one of embodiments 62-64, wherein thesecond N-terminal spacer domain comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 20-95, 235, 268, 269,303-305, 323-338, 340, 341, 727, 794, and 799.

66. The masked cytokine of any one of embodiments 62-65, wherein thesecond C-terminal spacer domain comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 20-95, 235, 268, 269,303-305, 323-338, 340, 341, 727, 794, and 799.

67. The masked cytokine of embodiment 62 or embodiment 63, wherein thesecond cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

68. The masked cytokine of embodiment 67, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

69. The masked cytokine of any one of embodiments 3-68, wherein thesecond linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812.

70. A masked cytokine comprising:

-   -   a) a first masking moiety;    -   b) a cytokine or functional fragment thereof,    -   wherein the first masking moiety is linked to the cytokine or        functional fragment thereof via a first linker; and    -   c) a second masking moiety,    -   wherein the second masking moiety is linked to the cytokine or        functional fragment thereof via a second linker.

71. The masked cytokine of embodiment 70, further comprising a half-lifeextension domain that is linked to either the first masking moiety orthe second masking moiety.

72. The masked cytokine of embodiment 71, wherein the half-lifeextension domain is linked to either the first masking moiety or thesecond masking moiety via a third linker.

73. The masked cytokine of embodiment 71 or embodiment 72, wherein:

-   -   i) the masked cytokine comprises in an N to C-terminal or in a C        to N-terminal direction: a) the first masking moiety; b) the        first linker; c) the cytokine or functional fragment thereof; d)        the second linker; e) the second masking moiety; and f) the        half-life extension domain;    -   ii) the masked cytokine comprises in an N to C-terminal or in a        C to N-terminal direction: a) the first masking moiety; b) the        first linker; c) the cytokine or functional fragment thereof; d)        the second linker; e) the second masking moiety; f) the third        linker; and g) the half-life extension domain;    -   iii) the masked cytokine comprises in an N to C-terminal or in a        C to N-terminal direction: a) the second masking moiety; b) the        second linker; c) the cytokine or functional fragment        thereof; d) the first linker; e) the first masking moiety;        and f) the half-life extension domain; or    -   iv) the masked cytokine comprises in an N to C-terminal or in a        C to N-terminal direction: a) the second masking moiety; b) the        second linker; c) the cytokine or functional fragment        thereof; d) the first linker; e) the first masking moiety; f)        the third linker; and g) the half-life extension domain.

74. The masked cytokine of any one of embodiments 70-73, wherein thecytokine or functional fragment thereof is an IL-2 polypeptide orfunctional fragment thereof.

75. The masked cytokine of embodiment 74, wherein the IL-2 polypeptideor functional fragment thereof comprises:

-   -   a) an amino acid sequence selected from the group consisting of        SEQ ID NOs: 1-8, 160, 230, 243-251, 260, 775-792, and 813-822;        or    -   b) an amino acid sequence produced by introducing one or more of        the following amino acid substitutions into any one of SEQ ID        NOs: 1-8, 160, 243-251, 260, 775-792, and 813-822: H161, L18C,        D20A, D20L, D20F, N29L, R38A, F42A, F42K, F42E, F43A, Y45A,        Y45N, Y45R, E62A, E62R, E62S, L72G, L80F, R81D, L85V, I86V,        I92F, and C125S.

76. The masked cytokine of embodiment 74 or embodiment 75, wherein thefirst masking moiety comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 9, 10, 161-165, 187-218, 221-229, 231,and 261, and the second masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 9, 10, 161-165,187-218, 221-229, 231, and 261, and wherein the amino acid sequence ofthe first masking moiety and the second masking moiety are different.

77. The masked cytokine of any one of embodiments 74-76, wherein:

-   -   a) the first masking moiety comprises the amino acid sequence of        SEQ ID NO: 9 or 231, and the second masking moiety comprises an        amino acid sequence selected from the group consisting of SEQ ID        NOs: 10, 161-165, 187-218, 221-226, and 261; or    -   b) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        187-218, 221-226, and 261, and the second masking moiety        comprises the amino acid sequence of SEQ ID NO: 9 or 231.

78. The masked cytokine of any one of embodiments 70-73, wherein thecytokine or functional fragment thereof is an IL-15 polypeptide orfunctional fragment thereof.

79. The masked cytokine of embodiment 78, wherein the IL-15 polypeptideor functional fragment thereof comprises the amino acid sequence of SEQID NO: 167.

80. The masked cytokine of embodiment 78 or embodiment 79, wherein:

-   -   a) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 232-234, and        823-825, and the second masking moiety comprises an amino acid        sequence selected from the group consisting of SEQ ID NOs: 10,        161-165, 219-229, and 261;    -   b) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        219-229, and 261, and the second masking moiety comprises an        amino acid sequence selected from the group consisting of SEQ ID        NOs: 232-234, and 823-825;    -   c) the first masking moiety comprises an amino acid sequence        produced by introducing one or more of the following amino acid        substitutions into the amino acid sequence of any one of SEQ ID        NOs: 232-234, and 823-825: R24A, R26A, K34A, 540A, L42A, and        P67A, and the second masking moiety comprises an amino acid        sequence selected from the group consisting of SEQ ID NOs: 10,        161-165, 219-229, and 261; or    -   d) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        219-229, and 261, and the second masking moiety comprises an        amino acid sequence produced by introducing one or more of the        following amino acid substitutions into the amino acid sequence        of any one of SEQ ID NOs: 232-234, and 823-825: R24A, R26A,        K34A, 540A, L42A, and P67A.

81. The masked cytokine of any one of embodiments 71-80, wherein thehalf-life extension domain is an antibody or fragment thereof.

82. The masked cytokine of embodiment 81, wherein the antibody orfragment thereof comprises either a heavy chain polypeptide or a lightchain polypeptide.

83. The masked cytokine of embodiment 82, wherein the heavy chainpolypeptide comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 158, 168, and 169.

84. The masked cytokine of embodiment 82, wherein the heavy chainpolypeptide comprises one or more amino acid substitutions alteringeffector function.

85. The masked cytokine of embodiment 84, wherein the heavy chainpolypeptide:

-   -   a) is an IgG1 heavy chain polypeptide and comprises the amino        acid substitution(s):        -   i) N297A, N297G, or N297Q;        -   ii) L234A and L235A;        -   iii) C220S, C226S, C229S, and P238S;        -   iv) C226S, C229S, E233P, L234V, and L235A;        -   v) L234F, L235E, and P331S;        -   vi) S267E and L328F;        -   vii) D265A;        -   viii) L234A, L235A, and P329G;    -   b) is an IgG2 heavy chain polypeptide and comprises the amino        acid substitution(s):        -   i) V234A and G237A;        -   ii) H268Q, V309L, A330S, and A331S; or        -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or    -   e) is an IgG4 heavy chain polypeptide and comprises the amino        acid substitution(s):        -   i) L235A, G237A, and E318A;        -   ii) S228P, L234A, and L235A;        -   iii) H268Q, V309L, A330S, and P331S; or        -   iv) S228P and L235A, numbered according to the Kabat EU            numbering system.

86. The masked cytokine of embodiment 84, wherein the heavy chainpolypeptide comprises one or more amino acid substitutions enhancingeffector function.

87. The masked cytokine of embodiment 86, wherein the heavy chainpolypeptide is an IgG1 heavy chain polypeptide and comprises the aminoacid substitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;    -   m) K290E, S298G, and T299A;    -   n) K290E, S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;    -   p) K290N, S298G, T299A, and K326E;    -   q) K334V;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and I332N;    -   av) S239D and I332Q;    -   aw) S239E and I332D;    -   ax) S239E and I332N;    -   ay) S239E and I332Q;    -   az) S239N and I332D;    -   ba) S239N and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, 1332E, and either S239D or S239N;    -   br) A330L, 1332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;    -   ch) E318R;    -   ci) S324D, S324I or S324V;    -   cj) K326I or K326T;    -   ck) T335D, T335R, or T335Y;    -   cl) V240I and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

88. The masked cytokine of embodiment 82, wherein the light chainpolypeptide comprises the amino acid sequence of SEQ ID NO: 157 or 170.

89. The masked cytokine of embodiment 81, wherein the antibody orfragment thereof is a Fragment crystallizable domain (Fc domain) orfragment thereof.

90. The masked cytokine of embodiment 89, wherein the Fc domain orfragment thereof comprises one or more amino acid substitutions alteringeffector function.

91. The masked cytokine of embodiment 90, wherein the Fc domain orfragment thereof:

a) is an IgG1 Fc domain or fragment thereof and comprises the aminosubstitution(s):

-   -   i) N297A, N297G, or N297Q;    -   ii) L234A and L235A;    -   iii) C220S, C226S, C229S, and P238S;    -   iv) C226S, C229S, E233P, L234V, and L235A;    -   v) L234F, L235E, and P331S;    -   vi) S267E and L328F;    -   vii) D265A;    -   viii) L234A, L235A, and P329G;

b) is an IgG2 Fc domain or fragment thereof and comprises the amino acidsubstitution(s):

-   -   i) V234A and G237A;    -   ii) H268Q, V309L, A330S, and A331S; or    -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or

e) is an IgG4 Fc domain or fragment thereof and comprises the amino acidsubstitution(s):

-   -   i) L235A, G237A, and E318A;    -   ii) S228P, L234A, and L235A;    -   iii) H268Q, V309L, A330S, and P331S; or    -   iv) S228P and L235A, numbered according to the Kabat EU        numbering system.

92. The masked cytokine of embodiment 90, wherein the Fc domain orfragment thereof comprises one or more amino acid substitutionsenhancing effector function.

93. The masked cytokine of embodiment 92, wherein the Fc domain orfragment thereof is an IgG1 Fc domain or fragment thereof and comprisesthe amino acid substitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;    -   m) K290E, S298G, and T299A;    -   n) K290E, S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;    -   p) K290N, S298G, T299A, and K326E;    -   q) K334V;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and I332N;    -   av) S239D and I332Q;    -   aw) S239E and I332D;    -   ax) S239E and I332N;    -   ay) S239E and I332Q;    -   az) S239N and I332D;    -   ba) S239N and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, I332E, and either S239D or S239N;    -   br) A330L, I332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;    -   ch) E318R;    -   ci) S324D, S324I or S324V;    -   cj) K326I or K326T;    -   ck) T335D, T335R, or T335Y;    -   cl) V240I and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

94. The masked cytokine of embodiment 89, wherein the Fc domain orfragment thereof comprises the amino acid sequence of SEQ ID NO: 154.

95. The masked cytokine of any one of embodiments 71-77, wherein thehalf-life extension domain is an albumin polypeptide or functionalfragment thereof.

96. The masked cytokine of embodiment 95, wherein the albuminpolypeptide or functional fragment thereof comprises the amino acidsequence of SEQ ID NO: 171.

97. The masked cytokine of any one of embodiments 71-77, wherein thehalf-life extension domain is an albumin-binding protein or functionalfragment thereof.

98. The masked cytokine of embodiment 97, wherein the albumin-bindingprotein or functional fragment thereof comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 172-174 and 252-259.

99. The masked cytokine of any one of embodiments 71-77, wherein thehalf-life extension domain is an IgG-binding protein or functionalfragment thereof.

100. The masked cytokine of embodiment 99, wherein the IgG-bindingprotein or functional fragment thereof comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 175-186.

101. The masked cytokine of any one of embodiments 71-77, wherein thehalf-life extension domain is a polyamino acid sequence.

102. The masked cytokine of embodiment 101, wherein the polyamino acidsequence is a PAS polypeptide or an XTEN polypeptide.

103. The masked cytokine of embodiment 102, wherein the PAS polypeptidecomprises at least 25, at least 50, at least 100, at least 150, at least200, at least 250, at least 300, at least 400, at least 500, at least600, at least 700, at least 800, at least 900, at least 1000, at least1100, at least 1200, at least 1300, at least 1500, at least 2000, atleast 2500, or at least 3000 amino acid residues, wherein each aminoacid residue is either a proline or an alanine residue.

104. The masked cytokine of embodiment 102, wherein the PAS polypeptidecomprises at least 25, at least 50, at least 100, at least 150, at least200, at least 250, at least 300, at least 400, at least 500, at least600, at least 700, at least 800, at least 900, at least 1000, at least1100, at least 1200, at least 1300, at least 1500, at least 2000, atleast 2500, or at least 3000 amino acid residues, wherein each aminoacid residue is selected from the group consisting of a proline, analanine, and a serine residue.

105. The masked cytokine of embodiment 102, wherein the XTEN polypeptidecomprises an amino acid sequence of about 25 to about 500, about 200 toabout 1000, about 500 to about 1500, about 1000 to about 2000, or about1500 to about 3000 amino acid residues, wherein at least about 70%, 75%,80%, or 85% of the amino acid sequence consists of non-overlappingsequence motifs where each of the motifs has 5 to 100 amino acidresidues, 5 to 50 amino acids residues, or 9 to 36 amino acid residues,and wherein at least 90%, at least 91%, at least 92%, at least 93%, atleast 94%, at least 95%, at least 96%, at least 97%, at least 98%, atleast 99%, or 100% of each of the motifs consists of four, five, or sixtypes of amino acid residues selected from the group consisting ofglycine (G), alanine (A), serine (S), threonine (T), glutamate (E) andproline (P), and wherein the content of any one amino acid type in thefull-length XTEN polypeptide does not exceed about 40%, about 35%, about30%, about 25%, about 15%, about 10%, or about 8%.

106. The masked cytokine of any one of embodiments 70-105, wherein themasked cytokine further comprises one or more PEG polymer chainsattached to the masked cytokine.

107. The masked cytokine of embodiment 106, wherein the one or more PEGpolymer chains are attached to the cytokine or functional fragmentthereof and/or the half-life extension domain.

108. The masked cytokine of any one of embodiments 70-107, wherein themasked cytokine is modified, or is further modified, by altering theamino acid sequence of the masked cytokine such that one or moreadditional N-linked and/or O-linked glycosylation sites are created.

109. The masked cytokine of embodiment 108, wherein the masked cytokineis modified, or is further modified, by altering the amino acid sequenceof the masked cytokine such that one or more additionalasparagine-X-serine (N—X—S) and/or asparagine-X-threonine (N-X-T)tripeptide sequence(s) is/are introduced into the amino acid sequence ofthe masked cytokine, wherein X is any amino acid except proline.

110. The masked cytokine of embodiment 108 or embodiment 109, whereinthe masked cytokine is modified, or is further modified, by altering theamino acid sequence of the masked cytokine such that one or moreadditional serine or threonine residues is/are introduced into the aminoacid sequence of the masked cytokine.

111. The masked cytokine of any one of embodiments 70-110, wherein thefirst linker comprises a first cleavable peptide.

112. The masked cytokine of any one of embodiments 70-111, where thefirst linker comprises a first N-terminal spacer domain and/or a firstC-terminal spacer domain.

113. The masked cytokine of embodiment 112, wherein the first linkercomprises:

-   -   a) the first N-terminal spacer domain, the first cleavable        peptide, and the first C-terminal spacer domain;    -   b) the first N-terminal spacer domain and the first cleavable        peptide;    -   c) the first N-terminal spacer domain and the first C-terminal        spacer domain;    -   d) the first cleavable peptide and the first C-terminal spacer        domain;    -   e) the first N-terminal spacer domain; or    -   f) the first C-terminal spacer domain.

114. The masked cytokine of any one of embodiments 111-113, wherein thefirst cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

115. The masked cytokine of any one of embodiments 112-114, wherein thefirst N-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

116. The masked cytokine of any one of embodiments 112-115, wherein thefirst C-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

117. The masked cytokine of any one of embodiments 111-113, wherein thefirst cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

118. The masked cytokine of embodiment 117, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

119. The masked cytokine of any one of embodiments 70-118, wherein thefirst linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812.

120. The masked cytokine of any one of embodiments 70-119, wherein thesecond linker comprises a second cleavable peptide.

121. The masked cytokine of any one of embodiments 70-120, wherein thesecond linker comprises a second N-terminal spacer domain and/or asecond C-terminal spacer domain 122. The masked cytokine of embodiment121, wherein the second linker comprises:

-   -   a) the second N-terminal spacer domain, the second cleavable        peptide, and second first C-terminal spacer domain;    -   b) the second N-terminal spacer domain and the second cleavable        peptide;    -   c) the second N-terminal spacer domain and the second C-terminal        spacer domain;    -   d) the second cleavable peptide and the second C-terminal spacer        domain;    -   e) the second N-terminal spacer domain; or    -   f) the second C-terminal spacer domain.

123. The masked cytokine of any one of embodiments 120-122, wherein thesecond cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

124. The masked cytokine of any one of embodiments 121-123, wherein thesecond N-terminal spacer domain comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 20-95, 235, 268, 269,303-305, 323-338, 340, 341, 727, 794, and 799.

125. The masked cytokine of any one of embodiments 121-124, wherein thesecond C-terminal spacer domain comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 20-95, 235, 268, 269,303-305, 323-338, 340, 341, 727, 794, and 799.

126. The masked cytokine of any one of embodiments 120-122, wherein thesecond cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

127. The masked cytokine of embodiment 126, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

128. The masked cytokine of any one of embodiments 70-127, wherein thesecond linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812.

129. The masked cytokine of any one of embodiments 72-128, wherein thethird linker comprises a third cleavable peptide.

130. The masked cytokine of any one of embodiments 72-129, wherein thethird linker comprises a third N-terminal spacer domain and/or a thirdC-terminal spacer domain.

131. The masked cytokine of embodiment 130, wherein the third linkercomprises:

-   -   a) the third N-terminal spacer domain, the third cleavable        peptide, and third first C-terminal spacer domain;    -   b) the third N-terminal spacer domain and the third cleavable        peptide;    -   c) the third N-terminal spacer domain and the third C-terminal        spacer domain;    -   d) the third cleavable peptide and the third C-terminal spacer        domain;    -   e) the third N-terminal spacer domain; or    -   f) the third C-terminal spacer domain.

132. The masked cytokine of any one of embodiments 129-131, wherein thethird cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

133. The masked cytokine of any one of embodiments 130-132, wherein thethird N-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

134. The masked cytokine of any one of embodiments 130-133, wherein thethird C-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

135. The masked cytokine of any one of embodiments 129-131, wherein thethird cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

136. The masked cytokine of embodiment 135, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

137. The masked cytokine of any one of embodiments 72-136, wherein thethird linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812.

138. The masked cytokine of any one of embodiments 52-137, wherein thefirst cleavable peptide, the second cleavable peptide, and/or the thirdcleavable peptide is a substrate for a protease that is co-localized ina region or a tissue expressing a cytokine receptor.

139. The masked cytokine of embodiment 138, wherein the cytokinereceptor is an IL-2 cytokine receptor or an IL-15 cytokine receptor.

140. The masked cytokine of any one of embodiments 1-139, wherein one ormore of the first cleavable peptide, the second cleavable peptide, andthe third cleavable peptide is cleaved by one or more enzyme selectedfrom the group consisting of: ABHD12, ADAM12, ABHD12B, ABHD13, ABHD17A,ADAM19, ADAM20, ADAM21, ADAM28, ADAM30, ADAM33, ADAMS, ABHD17A,ADAMDEC1, ADAMTS1, ADAMTS10, ADAMTS12, ADAMTS13, ADAMTS14, ADAMTS15,ADAMTS16, ADAMTS17, ADAMTS18, ADAMTS19, ADAMTS2, ADAMTS20, ADAMTS3,ADAMTS4, ABHD17B, ADAMTS5, ADAMTS6, ADAMTS7, ADAMTS8, ADAMTS9, ADAMTSL1,ADAMTSL2, ADAMTSL3, ABHD17C, ADAMTSL5, ASTL, BMP1, CELA1, CELA2A,CELA2B, CELA3A, CELA3B, ADAM10, ADAM15, ADAM17, ADAMS, ADAMTS4, CTSE,CTSF, ADAMTSL4, CMA1, CTRB1, CTRC, CTSO, CTRL, CTSA, CTSW, CTSB, CTSC,CTSD, ESP1, CTSG, CTSH, GZMA, GZMB, GZMH, CTSK, GZMM, CTSL, CTSS, CTSV,CTSZ, HTRA4, KLK10, KLK11, KLK13, KLK14, KLK2, KLK4, DPP4, KLK6, KLK7,KLKB1, ECE1, ECE2, ECEL1, MASP2, MEP1A, MEP1B, ELANE, FAP, GZMA, MMP11,GZMK, HGFAC, HPN, HTRA1, MMP11, MMP16, MMP17, MMP19, HTRA2, MMP20,MMP21, HTRA3, HTRA4, KEL, MMP23B, MMP24, MMP25, MMP26, MMP27, MMP28,KLK5, MMP3, MMP1, MMP8, MMP9, LGMN, LNPEP, MASP1, PAPPA, PAPPA2, PCSK1,NAPSA, PCSK5, PCSK6, MME, MMP1, MMP10, PLAT, PLAU, PLG, PRSS1, PRSS12,PRSS2, PRSS21, PRSS3, PRSS33, PRSS4, PRSS55, PRSS57, MMP12, PRSS8,PRSS9, PRTN3, MMP13, MMP14, ST14, TMPRSS10, TMPRSS11A, TMPRSS11D,TMPRSS11E, TMPRSS11F, TMPRSS12, TMPRSS13, MMP15, TMPRSS15, MMP2,TMPRSS2, TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS6, TMPRSS7, TMPRSS9, NRDC,OVCH1, PAMR1, PCSK3, PHEX, TINAG, TPSAB1, TPSD1, and TPSG1.

141. The masked cytokine of any one of embodiments 2-69 and 71-140,wherein the half-life extension domain is conjugated to an agent.

142. The masked cytokine of embodiment 141, wherein the agent is aninhibitor of tubulin polymerization, a DNA damaging agent, or a DNAsynthesis inhibitor.

143. The masked cytokine of embodiment 142, wherein the agent is amaytansinoid, an auristatin, a pyrrolobenzodiazepine (PBD) dimer, acalicheamicin, a duocarmycin, a indo-linobenzodiazepine dimer orexatecan derivative Dxd.

144. The masked cytokine of embodiment 141, wherein the agent is animmune stimulant.

145. The masked cytokine of embodiment 144, wherein the immune stimulantis a stimulator of interferon genes (STING) agonist or a toll-likereceptor (TLR) agonist.

146. The masked cytokine of embodiment 145, wherein the STING agonist isa cyclic dinucleotide (CDN).

147. The masked cytokine of embodiment 146, wherein the CDN is selectedfrom the group consisting of cGAMP, c-di-AMP, c-di-GMP, cAIMP, c-di-IMP,4-(2-chloro-6-fluorobenzyl)-N-(furan-2-ylmethyl)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamide.

148. The masked cytokine of embodiment 145, wherein the TLR agonist isan agonist of a TLR selected from the group consisting of TLR1, TLR2,TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, and TLR10.

149. A masked cytokine comprising:

-   -   a) a first half-life extension domain and a second half-life        extension domain;    -   b) a masking moiety; and    -   c) a cytokine or functional fragment thereof,    -   wherein the masking moiety is linked to the first half-life        extension domain,    -   wherein the cytokine or functional fragment thereof is linked to        the second half-life extension domain, and    -   wherein the first half-life extension domain and the second        half-life extension domain contain modifications promoting the        association of the first and the second half-life extension        domain.

150. The masked cytokine of embodiment 149, wherein the masking moietyis linked to the first half-life extension domain via a first linker;and/or wherein the cytokine or functional fragment thereof is linked tothe second half-life extension domain via a second linker.

151. The masked cytokine of embodiment 149 or embodiment 150, whereinthe cytokine or functional fragment thereof is an IL-2 polypeptide orfunctional fragment thereof.

152. The masked cytokine of embodiment 151, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 1-8, 160, 230, 243-251, 260,775-792, and 813-822.

153. The masked cytokine of embodiment 151, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby introducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatreduces the affinity of the IL-2 polypeptide or functional fragmentthereof for CD25 (IL-2Rα).

154. The masked cytokine of embodiment 153, wherein the amino acidsequence is produced by introducing one or more of the following aminoacid substitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: R38A, F42A, F42K, F42E, K43A, Y45A, Y45N, Y45R,E62A, E62R, E62S, and L72G.

155. The masked cytokine of embodiment 151, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby introducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatincreases the affinity of the IL-2 polypeptide or functional fragmentthereof for IL-2Rβ or IL-2Rγ.

156. The masked cytokine of embodiment 155, wherein the amino acidsequence is produced by introducing one or more of the following aminoacid substitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: H161, L18C, D20A, D20L, D20F, N29L, L80F, R81D,L85V, I86V, and I92F.

157. The masked cytokine of embodiment 153 or embodiment 154, whereinthe amino acid sequence is produced by further introducing one or moreamino acid substitutions that increase the affinity of the IL-2polypeptide or functional fragment thereof for IL-2Rβ or IL-2Rγ.

158. The masked cytokine of embodiment 157, wherein the one or moreamino acid substitutions that increase the affinity of the IL-2polypeptide or functional fragment thereof for IL-2Rβ or IL-2Rγ isselected from the group consisting of H161, L18C, D20A, D20L, D20F,N29L, L80F, R81D, L85V, I86V, and I92F.

159. The masked cytokine of embodiment 151, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby introducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatstabilizes the IL-2 polypeptide or functional fragment thereof.

160. The masked cytokine of embodiment 159, wherein the amino acidsequence is produced by introducing one of the following amino acidsubstitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: C125S, C125A, and C125G.

161. The masked cytokine of any one of embodiments 153-158, wherein theamino acid sequence is produced by further introducing one or more aminoacid substitutions that stabilize the IL-2 polypeptide or functionalfragment thereof.

162. The masked cytokine of embodiment 161, wherein the one or moreamino acid substitutions that stabilize the IL-2 polypeptide orfunctional fragment thereof is the amino acid substitution C125S, C125A,or C125G.

163. The masked cytokine of any one of embodiments 151-162, wherein themasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 9, 10, 161-165, 187-218, 221-229, 231, 261,826 and 827.

164. The masked cytokine of embodiment 149 or embodiment 150, whereinthe cytokine or functional fragment thereof is an IL-15 polypeptide orfunctional fragment thereof.

165. The masked cytokine of embodiment 164, wherein the IL-15polypeptide or functional fragment thereof comprises the amino acidsequence of SEQ ID NO: 167.

166. The masked cytokine of embodiment 164 or embodiment 165, whereinthe masking moiety comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 10, 161-165, 219-229, 232-234, 261, and823-827.

167. The masked cytokine of embodiment 164 or embodiment 165, whereinthe masking moiety comprises an amino acid sequence produced byintroducing one or more of the following amino acid substitutions intothe amino acid sequence of any one of SEQ ID NOs: 232-234, and 823-825:R24A, R26A, K34A, 540A, L42A, and P67A.

168. The masked cytokine of any one of embodiment 149-167, wherein thefirst half-life extension domain is a first antibody or fragmentthereof, and the second half-life extension domain is a second antibodyor fragment thereof.

169. The masked cytokine of embodiment 168, wherein:

-   -   a) the first antibody or fragment thereof comprises a first        heavy chain polypeptide, and the second antibody or fragment        thereof comprises a second light chain polypeptide; or    -   b) the first antibody or fragment thereof comprises a first        light chain polypeptide, and the second antibody or fragment        thereof comprises a second heavy chain polypeptide.

170. The masked cytokine of embodiment 169, wherein the first heavychain polypeptide or the second heavy chain polypeptide comprises one ormore amino acid substitutions altering effector function.

171. The masked cytokine of embodiment 170, wherein the first heavychain polypeptide or the second heavy chain polypeptide:

a) is an IgG1 isotype and comprises the amino substitution(s):

-   -   i) N297A, N297G, or N297Q;    -   ii) L234A and L235A;    -   iii) C220S, C226S, C229S, and P238S;    -   iv) C226S, C229S, E233P, L234V, and L235A;    -   v) L234F, L235E, and P331S;    -   vi) S267E and L328F;    -   vii) D265A;    -   viii) L234A, L235A, and P329G;

b) is an IgG2 isotype and comprises the amino acid substitution(s):

-   -   i) V234A and G237A;    -   ii) H268Q, V309L, A330S, and A331S; or    -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or

e) is an IgG4 isotype and comprises the amino acid substitution(s):

-   -   i) L235A, G237A, and E318A;    -   ii) S228P, L234A, and L235A;    -   iii) H268Q, V309L, A330S, and P331S; or    -   iv) S228P and L235A, numbered according to the Kabat EU        numbering system.

172. The masked cytokine of embodiment 170, wherein the first heavychain polypeptide or the second heavy chain polypeptide comprises one ormore amino acid substitutions enhancing effector function.

173. The masked cytokine of embodiment 172, wherein the first heavychain polypeptide or the second heavy chain polypeptide is an IgG1 heavychain polypeptide and comprises the amino acid substitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;    -   m) K290E, S298G, and T299A;    -   n) K290E, S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;    -   p) K290N, S298G, T299A, and K326E;    -   q) K334V;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and 1332N;    -   av) S239D and I332Q;    -   aw) S239E and I332D;    -   ax) S239E and I332N;    -   ay) S239E and I332Q;    -   az) S239N and I332D;    -   ba) S239N and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, I332E, and either S239D or S239N;    -   br) A330L, I332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;    -   ch) E318R;    -   ci) S324D, S324I or S324V;    -   cj) K326I or K326T;    -   ck) T335D, T335R, or T335Y;    -   cl) V240I and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

174. The masked cytokine of embodiment 169, wherein the first heavychain polypeptide comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 158, 168, and 169, and the second heavychain polypeptide comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 158, 168, and 169.

175. The masked cytokine of embodiment 169, wherein the first lightchain polypeptide comprises the amino acid sequence of SEQ ID NO: 157 or170, and the second light chain polypeptide comprises the amino acidsequence of SEQ ID NO: 157 or 170.

176. The masked cytokine of embodiment 168, wherein the first antibodyor fragment thereof is a first Fragment crystallizable domain (Fcdomain) or fragment thereof, and the second antibody or fragment thereofis a second Fc domain or fragment thereof.

177. The masked cytokine of embodiment 176, wherein the first Fc domainor fragment thereof, and/or the second Fc domain or fragment thereofcomprises one or more amino acid substitutions altering effectorfunction.

178. The masked cytokine of embodiment 177, wherein the first Fc domainor fragment thereof and/or the second Fc domain or fragment thereof:

-   -   a) is an IgG1 Fc domain or fragment thereof and comprises the        amino substitution(s):        -   i) N297A, N297G, or N297Q;        -   ii) L234A and L235A;        -   iii) C220S, C226S, C229S, and P238S;        -   iv) C226S, C229S, E233P, L234V, and L235A;        -   v) L234F, L235E, and P331S;        -   vi) S267E and L328F;        -   vii) D265A;        -   viii) L234A, L235A, and P329G;    -   b) is an IgG2 Fc domain or fragment thereof and comprises the        amino acid substitution(s):        -   i) V234A and G237A;        -   ii) H268Q, V309L, A330S, and A331S; or        -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or    -   e) is an IgG4 Fc domain or fragment thereof and comprises the        amino acid substitution(s):        -   i) L235A, G237A, and E318A;        -   ii) S228P, L234A, and L235A;        -   iii) H268Q, V309L, A330S, and P331S; or        -   iv) S228P and L235A, numbered according to the Kabat EU            numbering system.

179. The masked cytokine of embodiment 177, wherein the first Fc domainor fragment thereof, and/or the second Fc domain or fragment thereofcomprises one or more amino acid substitutions enhancing effectorfunction.

180. The masked cytokine of embodiment 179, wherein the first Fc domainor fragment thereof and/or the second Fc domain or fragment thereof isan IgG1 Fc domain or fragment thereof and comprises the amino acidsubstitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;    -   m) K290E, S298G, and T299A;    -   n) K290E, S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;    -   p) K290N, S298G, T299A, and K326E;    -   q) K334V;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and I332N;    -   av) S239D and 1332Q;    -   aw) S239E and I332D;    -   ax) S239E and I332N;    -   ay) S239E and I332Q;    -   az) S239N and I332D;    -   ba) S239N and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, 1332E, and either S239D or S239N;    -   br) A330L, 1332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;    -   ch) E318R;    -   ci) S324D, S324I or S324V;    -   cj) K326I or K326T;    -   ck) T335D, T335R, or T335Y;    -   cl) V240I and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

181. The masked cytokine of embodiment 176, wherein:

-   -   a) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 155, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        156;    -   b) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 156, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        155;    -   c) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 154, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        154;    -   d) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 265, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        156;    -   e) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 156, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        265;    -   f) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 155, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        616;    -   g) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 616, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        155;    -   h) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 157, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        158;    -   i) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 158, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        157;    -   j) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 796, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        774;    -   k) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 774, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        796;    -   l) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 721, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        619;    -   m) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 619, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        721;    -   n) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 721, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        772;    -   o) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 772, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        721;    -   p) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 793, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        622;    -   q) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 622, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        793;    -   r) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 793, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        773;    -   s) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 773, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        793;    -   t) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 796, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        625;    -   u) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 625, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        796;    -   v) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 156, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        156;    -   w) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 796, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        625; or    -   x) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 625, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        796.

182. The masked cytokine of any one of embodiments 149-167, wherein thefirst half-life extension domain is a first scFv or fragment thereof,and the second half-life extension domain is a second scFv or fragmentthereof.

183. The masked cytokine of any one of embodiments 149-167, wherein thefirst half-life extension domain is a first Fc domain or fragmentthereof, and the second half-life extension domain is a second Fc domainor fragment thereof, and wherein the first Fc domain or fragment thereofis linked to the second Fc domain or fragment thereof.

184. The masked cytokine of embodiment 183, wherein the first Fc domainor fragment thereof is linked to the second Fc domain or fragmentthereof via a third linker.

185. The masked cytokine of any one of embodiments 149-167, wherein:

-   -   a) the first half-life extension domain is an scFv or fragment        thereof, and the second half-life extension domain is an        antibody or fragment thereof; or    -   b) the first half-life extension domain is an antibody or        fragment thereof, and the second half-life extension domain is        an scFv or fragment thereof.

186. The masked cytokine of any one of embodiments 168-181, wherein themodifications promoting the association of the first and the secondhalf-life extension domain comprise:

-   -   a) introducing S354C and T366W mutations in the first antibody        or fragment thereof, and introducing Y349C, T366S, L368A, and        Y407V mutations in the second antibody or fragment thereof,        numbered according to the Kabat EU numbering system;    -   b) introducing S354C and T366W mutations in the second antibody        or fragment thereof, and introducing Y349C, T366S, L368A, and        Y407V mutations in the first antibody or fragment thereof,        numbered according to the Kabat EU numbering system;    -   c) introducing K392D and K409D mutations in the first antibody        or fragment thereof, and introducing D399K and E356K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   d) introducing K392D and K409D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   e) introducing S364H and F405A mutations in the first antibody        or fragment thereof, and introducing Y349T and T394F mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system; or    -   f) introducing S364H and F405A mutations in the second antibody        or fragment thereof, and introducing Y349T and T394F mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system.

187. The masked cytokine of any one of embodiments 168-181, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing S354C and T366W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349C, T366S,        L368A, and Y407V mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, respectively, numbered according to the Kabat EU        numbering system;    -   b) introducing S354C and T366W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349C, T366S,        L368A, and Y407V mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, respectively, numbered according to the Kabat EU        numbering system;    -   c) introducing K392D and K409D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   d) introducing K392D and K409D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   e) introducing S364H and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349T and        T394F mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system; or    -   f) introducing S364H and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349T and        T394F mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system.

188. The masked cytokine of any one of embodiments 168-181, wherein themodifications promoting the association of the first and the secondhalf-life extension domain comprise:

-   -   a) introducing a Y407T mutation in the first antibody or        fragment thereof, and introducing a T366Y mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   b) introducing a Y407A mutation in the first antibody or        fragment thereof, and introducing a T366W mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   c) introducing a F405A mutation in the first antibody or        fragment thereof, and introducing a T394W mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   d) introducing a F405W mutation in the first antibody or        fragment thereof, and introducing a T394S mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   e) introducing a Y407T mutation in the first antibody or        fragment thereof, and introducing a T366Y mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   f) introducing T366Y and F405A mutations in the first antibody        or fragment thereof, and introducing T394W and Y407T mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   g) introducing T366W and F405W mutations in the first antibody        or fragment thereof, and introducing T394S and Y407A mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   h) introducing F405W and Y407A mutations in the first antibody        or fragment thereof, and introducing T366W and T394S mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   i) introducing a T366W mutation in the first antibody or        fragment thereof, and introducing T366S, L368A, and Y407V        mutations in the second antibody or fragment thereof, numbered        according to the Kabat EU numbering system;    -   j) introducing a Y407T mutation in the second antibody or        fragment thereof, and introducing a T366Y mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   k) introducing a Y407A mutation in the second antibody or        fragment thereof, and introducing a T366W mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   l) introducing a F405A mutation in the second antibody or        fragment thereof, and introducing a T394W mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   m) introducing a F405W mutation in the second antibody or        fragment thereof, and introducing a T394S mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   n) introducing a Y407T mutation in the second antibody or        fragment thereof, and introducing a T366Y mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   o) introducing T366Y and F405A mutations in the second antibody        or fragment thereof, and introducing T394W and Y407T mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   p) introducing T366W and F405W mutations in the second antibody        or fragment thereof, and introducing T394S and Y407A mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   q) introducing F405W and Y407A mutations in the second antibody        or fragment thereof, and introducing T366W and T394S mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system; or    -   r) introducing a T366W mutation in the second antibody or        fragment thereof, and introducing T366S, L368A, and Y407V        mutations in the first antibody or fragment thereof, numbered        according to the Kabat EU numbering system.

189. The masked cytokine of any one of embodiments 168-181, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   b) introducing a Y407A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;        F405A mutation in the amino acid sequence of SEQ ID NO: 154 or        169, and introducing a T394W mutation in the amino acid sequence        of SEQ ID NO: 154 or 169, respectively, numbered according to        the Kabat EU numbering system;    -   d) introducing a F405W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394S mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   e) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   f) introducing T366Y and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394W and        Y407T mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   g) introducing T366W and F405W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394S and        Y407A mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   h) introducing F405W and Y407A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T366W and        T394S mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   i) introducing a T366W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing T366S, L368A, and Y407V        mutations in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   j) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   k) introducing a Y407A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   l) introducing a F405A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   m) introducing a F405W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394S mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   n) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        rding to the Kabat EU numbering system;        T366Y and F405A mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, and introducing T394W and Y407T mutations in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   p) introducing T366W and F405W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394S and        Y407A mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   q) introducing F405W and Y407A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T366W and        T394S mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system; or    -   r) introducing a T366W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing T366S, L368A, and Y407V        mutations in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system.

190. The masked cytokine of any one of embodiments 168-181, wherein themodifications promoting the association of the first and the secondhalf-life extension domain comprise:

-   -   a) introducing a K409E mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   b) introducing a K409E mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   c) introducing a K409D mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   d) introducing a K409D mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   e) introducing a K392E mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   f) introducing a K392E mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   g) introducing a K392D mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        :em;        K392D mutation in the first antibody or fragment thereof, and        introducing a D399K mutation in the second antibody or fragment        thereof, numbered according to the Kabat EU numbering system;    -   i) introducing K409D and K360D mutations in the first antibody        or fragment thereof, and introducing D399K and E356K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   j) introducing K409D and K370D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   k) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K, E356K, and E357K        mutations in the second antibody or fragment thereof, numbered        according to the Kabat EU numbering system;    -   l) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing a D399K mutation in the        second antibody or fragment thereof, numbered according to the        Kabat EU numbering system;    -   m) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K and E356K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   n) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   o) introducing K409D and K370D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   p) introducing a D399K mutation in the first antibody or        fragment thereof, and introducing K409D and K360D mutations in        the second antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   q) introducing K409D and K439D mutations in the first antibody        or fragment thereof, and introducing D399K and E356K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   r) introducing a K409E mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   s) introducing a K409E mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        :em;        K409D mutation in the second antibody or fragment thereof, and        introducing a D399K mutation in the first antibody or fragment        thereof, numbered according to the Kabat EU numbering system;    -   u) introducing a K409D mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   v) introducing a K392E mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   w) introducing a K392E mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   x) introducing a K392D mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   y) introducing a K392D mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   z) introducing K409D and K360D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   aa) introducing K409D and K370D mutations in the second antibody        or fragment thereof, and introducing D399K and E357K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   ab) introducing K409D and K392D mutations in the second antibody        or fragment thereof, and introducing D399K, E356K, and E357K        mutations in the first antibody or fragment thereof, numbered        according to the Kabat EU numbering system;    -   ac) introducing K409D and K392D mutations in the second antibody        or fragment thereof, and introducing a D399K mutation in the        first antibody or fragment thereof, numbered according to the        Kabat EU numbering system;    -   ad) introducing K409D and K392D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   ae) introducing K409D and K392D mutations in the second antibody        or fragment thereof, and introducing D399K and E357K mutations        in the first antibody or fragment thereof, numbered according        -   J numbering system;            -   K409D and K370D mutations in the second antibody or                fragment thereof, and introducing D399K and E357K                mutations in the first antibody or fragment thereof,                numbered according to the Kabat EU numbering system;    -   ag) introducing a D399K mutation in the second antibody or        fragment thereof, and introducing K409D and K360D mutations in        the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system; or    -   ah) introducing K409D and K439D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system.

191. The masked cytokine of any one of embodiments 168-181, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   b) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   c) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   d) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   e) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   f) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   g) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;        K392D mutation in the amino acid sequence of SEQ ID NO: 154 or        169, and introducing a D399K mutation in the amino acid sequence        of SEQ ID NO: 154 or 169, respectively, numbered according to        the Kabat EU numbering system;    -   i) introducing K409D and K360D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   j) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   k) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K, E356K,        and E357K mutations in the amino acid sequence of SEQ ID NO: 154        or 169, respectively, numbered according to the Kabat EU        numbering system;    -   l) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing a D399K        mutation in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   m) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   n) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   o) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   p) introducing a D399K mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing K409D and K360D mutations        in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   q) introducing K409D and K439D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   r) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   s) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        rding to the Kabat EU numbering system;        K409D mutation in the amino acid sequence of SEQ ID NO: 154 or        169, and introducing a D399K mutation in the amino acid sequence        of SEQ ID NO: 154 or 169, respectively, numbered according to        the Kabat EU numbering system;    -   u) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   v) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   w) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   x) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   y) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   z) introducing K409D and K360D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   aa) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   ab) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K, E356K,        and E357K mutations in the amino acid sequence of SEQ ID NO: 154        or 169, respectively, numbered according to the Kabat EU        numbering system;    -   ac) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing a D399K        mutation in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   ad) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, numbered according to the Kabat EU numbering system;    -   ae) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        ly, numbered according to the Kabat EU numbering system;        K409D and K370D mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, and introducing D399K and E357K mutations in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   ag) introducing a D399K mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing K409D and K360D mutations        in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system; or    -   ah) introducing K409D and K439D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system.

192. The masked cytokine of any one of embodiments 150-191, wherein thefirst linker comprises a first cleavable peptide; and/or wherein thesecond linker comprises a second cleavable peptide.

193. The masked cytokine of any one of embodiments 150-192, wherein thefirst linker comprises a first N-terminal spacer domain, and/or a firstC-terminal spacer domain.

194. The masked cytokine of embodiment 193, wherein the first linkercomprises:

-   -   a) the first N-terminal spacer domain, the first cleavable        peptide, and the first C-terminal spacer domain;    -   b) the first N-terminal spacer domain and the first cleavable        peptide;    -   c) the first N-terminal spacer domain and the first C-terminal        spacer domain;    -   d) the first cleavable peptide and the first C-terminal spacer        domain;    -   e) the first N-terminal spacer domain; or    -   f) the first C-terminal spacer domain.

195. The masked cytokine of any one of embodiments 150-194, wherein thesecond linker comprises a second N-terminal spacer domain, and/or asecond C-terminal spacer domain.

196. The masked cytokine of embodiment 195, wherein the second linkercomprises:

-   -   a) the second N-terminal spacer domain, the second cleavable        peptide, and the second C-terminal spacer domain;    -   b) the second N-terminal spacer domain and the second cleavable        peptide;    -   c) the second N-terminal spacer domain and the second C-terminal        spacer domain;    -   d) the second cleavable peptide and the second C-terminal spacer        domain;        econd N-terminal spacer domain; or        -terminal spacer domain.

197. The masked cytokine of any one of embodiments 192-196, wherein thefirst cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555;and/or wherein the second cleavable peptide comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153,236-242, 264, 270-302, 306-317, 342-347, 356-415, 420-491, 494-501,504-535, and 538-555.

198. The masked cytokine of any one of embodiments 193-197, wherein thefirst N-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95 235, 263, 268, 269, 727,794, 799, and 857-878, and/or the first C-terminal spacer domaincomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340, 341, 727, 794,and 799.

199. The masked cytokine of any one of embodiments 192-196, wherein thefirst cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

200. The masked cytokine of embodiment 199, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

201. The masked cytokine of any one of embodiments 195-200, wherein thesecond N-terminal spacer domain comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 20-95, 235, 268, 269,303-305, 323-338, 340, 341, 727, 794, and 799, and/or the secondC-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

202. The masked cytokine of any one of embodiments 192-201, wherein thesecond cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153,

342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

203. The masked cytokine of embodiment 202, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

204. The masked cytokine of any one of embodiments 150-203, wherein thefirst linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812,and/or the second linker comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320,323-338, 340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and797-812.

205. The masked cytokine of any one of embodiments 184-204, wherein thethird linker comprises a third N-terminal spacer domain, and/or a thirdC-terminal spacer domain.

206. The masked cytokine of embodiment 205, wherein the third N-terminalspacer domain comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340,341, 727, 794, and 799, and/or the third C-terminal spacer domaincomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340, 341, 727, 794,and 799.

207. The masked cytokine of any one of embodiments 192-206, wherein thefirst cleavable peptide and/or the second cleavable peptide is asubstrate for a protease that is co-localized in a region or a tissueexpressing a cytokine receptor.

208. The masked cytokine of embodiment 207, wherein the cytokinereceptor is an IL-2 cytokine receptor or an IL-15 cytokine receptor.

209. The masked cytokine of any one of embodiments 184-208, wherein thefirst cleavable peptide and/or the second cleavable peptide is cleavedby one or more enzyme selected from the group

ABHD12, ADAM12, ABHD12B, ABHD13, ABHD17A, ADAM19, ADAM20,

kDAM30, ADAM33, ADAMS, ABHD17A, ADAMDEC1, ADAMTS1, ADAMTS10, ADAMTS12,ADAMTS13, ADAMTS14, ADAMTS15, ADAMTS16, ADAMTS17, ADAMTS18, ADAMTS19,ADAMTS2, ADAMTS20, ADAMTS3, ADAMTS4, ABHD17B, ADAMTS5, ADAMTS6, ADAMTS7,ADAMTS8, ADAMTS9, ADAMTSL1, ADAMTSL2, ADAMTSL3, ABHD17C, ADAMTSL5, ASTL,BMP1, CELA1, CELA2A, CELA2B, CELA3A, CELA3B, ADAM10, ADAM15, ADAM17,ADAMS, ADAMTS4, CTSE, CTSF, ADAMTSL4, CMA1, CTRB1, CTRC, CTSO, CTR1,CTSA, CTSW, CTSB, CTSC, CTSD, ESP1, CTSG, CTSH, GZMA, GZMB, GZMH, CTSK,GZMM, CTSL, CTSS, CTSV, CTSZ, HTRA4, KLK10, KLK11, KLK13, KLK14, KLK2,KLK4, DPP4, KLK6, KLK7, KLKB1, ECE1, ECE2, ECEL1, MASP2, MEP1A, MEP1B,ELANE, FAP, GZMA, MMP11, GZMK, HGFAC, HPN, HTRA1, MMP11, MMP16, MMP17,MMP19, HTRA2, MMP20, MMP21, HTRA3, HTRA4, KEL, MMP23B, MMP24, MMP25,MMP26, MMP27, MMP28, KLK5, MMP3, MMP1, MMP8, MMP9, LGMN, LNPEP, MASP1,PAPPA, PAPPA2, PCSK1, NAPSA, PCSK5, PCSK6, MME, MMP1, MMP10, PLAT, PLAU,PLG, PRSS1, PRSS12, PRSS2, PRSS21, PRSS3, PRSS33, PRSS4, PRSS55, PRSS57,MMP12, PRSS8, PRSS9, PRTN3, MMP13, MMP14, ST14, TMPRSS10, TMPRSS11A,TMPRSS11D, TMPRSS11E, TMPRSS11F, TMPRSS12, TMPRSS13, MMP15, TMPRSS15,MMP2, TMPRSS2, TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS6, TMPRSS7, TMPRSS9,NRDC, OVCH1, PAMR1, PCSK3, PHEX, TINAG, TPSAB1, TPSD1, and TPSG1.

210. The masked cytokine of any one of embodiments 149-209, wherein thefirst half-life extension domain and/or the second half-life extensiondomain is conjugated to an agent.

211. The masked cytokine of embodiment 210, wherein the agent is aninhibitor of tubulin polymerization, a DNA damaging agent, or a DNAsynthesis inhibitor.

212. The masked cytokine of embodiment 211, wherein the agent is amaytansinoid, an auristatin, a pyrrolobenzodiazepine (PBD) dimer, acalicheamicin, a duocarmycin, a indo-linobenzodiazepine dimer orexatecan derivative Dxd.

213. The masked cytokine of embodiment 210, wherein the agent is animmune stimulant.

214. The masked cytokine of embodiment 213, wherein the immune stimulantis a stimulator of interferon genes (STING) agonist or a toll-likereceptor (TLR) agonist.

215. The masked cytokine of embodiment 214, wherein the STING agonist isa cyclic

DN).

216. The masked cytokine of embodiment 215, wherein the CDN is selectedfrom the group consisting of cGAMP, c-di-AMP, c-di-GMP, cAIMP, c-di-IMP,4-(2-chloro-6-fluorobenzyl)-N-(furan-2-ylmethyl)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamide.

217. The masked cytokine of embodiment 214, wherein the TLR agonist isan agonist of a TLR selected from the group consisting of TLR1, TLR2,TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, and TLR10.

218. A masked cytokine comprising:

-   -   a) a first half-life extension domain and a second half-life        extension domain;    -   b) a first masking moiety and a second masking moiety; and    -   c) a cytokine or functional fragment thereof,    -   wherein the first masking moiety is linked to the first        half-life extension domain,    -   wherein the second masking moiety is linked to the cytokine or        functional fragment thereof,    -   wherein either the second masking moiety or the cytokine or        functional fragment thereof is linked to the second half-life        extension domain, and    -   wherein the first half-life extension domain and the second        half-life extension domain contain modifications promoting the        association of the first and the second half-life extension        domain.

219. The masked cytokine of embodiment 218, wherein:

-   -   a) the first masking moiety is linked to the first half-life        extension domain via a first linker; and/or    -   b) either the second masking moiety or the cytokine or        functional fragment thereof is linked to the second half-life        extension domain via a second linker.

220. The masked cytokine of embodiment 218 or embodiment 219, whereinthe second masking moiety is linked to the cytokine or functionalfragment thereof via a third linker.

221. The masked cytokine of any one of embodiments 218-220, wherein thecytokine or functional fragment thereof is an IL-2 polypeptide orfunctional fragment thereof.

222. The masked cytokine of embodiment 221, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 1-8, 160, 243-251, 230,243-251, 260, 775-792, and 813-822.

tsked cytokine of embodiment 221, wherein the IL-2 polypeptide orfunctional fragment thereof comprises an amino acid sequence produced byintroducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatreduces the affinity of the IL-2 polypeptide or functional fragmentthereof for CD25 (IL-2Rα).

224. The masked cytokine of embodiment 223, wherein the amino acidsequence is produced by introducing one or more of the following aminoacid substitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: R38A, F42A, F42K, F42E, K43A, Y45A, Y45N, Y45R,E62A, E62R, E62S, and L72G.

225. The masked cytokine of embodiment 221, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby introducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatincreases the affinity of the IL-2 polypeptide or functional fragmentthereof for IL-2Rβ or IL-2Rγ.

226. The masked cytokine of embodiment 225, wherein the amino acidsequence is produced by introducing one or more of the following aminoacid substitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: H161, L18C, D20A, D20L, D20F, N29L, L80F, R81D,L85V, I86V, and I92F.

227. The masked cytokine of embodiment 223 or embodiment 224, whereinthe amino acid sequence is produced by further introducing one or moreamino acid substitutions that increase the affinity of the IL-2polypeptide or functional fragment thereof for IL-2Rβ or IL-2Rγ.

228. The masked cytokine of embodiment 227, wherein the one or moreamino acid substitutions that increase the affinity of the IL-2polypeptide or functional fragment thereof for IL-2Rβ or IL-2Rγ isselected from the group consisting of H161, L18C, D20A, D20L, D20F,N29L, L80F, R81D, L85V, I86V, and I92F.

229. The masked cytokine of embodiment 221, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby introducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatstabilizes the IL-2 polypeptide or functional fragment thereof.

tsked cytokine of embodiment 229, wherein the amino acid sequence isproduced by introducing one of the following amino acid substitutionsinto any one of SEQ ID NOs: 1-8, 160, 243-251, 260, 775-792, and813-822: C125S, C125A, and C125G.

231. The masked cytokine of any one of embodiments 223-228, wherein theamino acid sequence is produced by further introducing one or more aminoacid substitutions that stabilize the IL-2 polypeptide or functionalfragment thereof.

232. The masked cytokine of embodiment 231, wherein the one or moreamino acid substitutions that stabilize the IL-2 polypeptide orfunctional fragment thereof is the amino acid substitution C125S, C125A,or C125G.

233. The masked cytokine of any one of embodiments 221-232, wherein thefirst masking moiety comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 9, 10, 161-165, 187-218, 221-229, 231,261, 826 and 827 and the second masking moiety comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 9, 10,161-165, 187-218, 221-229, 231, 261, 826 and 827 and wherein the aminoacid sequence of the first masking moiety and the second masking moietyare different.

234. The masked cytokine of any one of embodiments 221-233, wherein:

-   -   a) the first masking moiety comprises the amino acid sequence of        SEQ ID NO: 9 or 231, and the second masking moiety comprises an        amino acid sequence selected from the group consisting of SEQ ID        NOs: 10, 161-165, 187-218, 221-226, 261, 826 and 827; or    -   b) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        187-218, 221-226, 261, 826 and 827, and the second masking        moiety comprises the amino acid sequence of SEQ ID NO: 9 or 231.

235. The masked cytokine of any one of embodiments 218-220, wherein thecytokine or functional fragment thereof is an IL-15 polypeptide orfunctional fragment thereof.

236. The masked cytokine of embodiment 235, wherein the IL-15polypeptide or functional fragment thereof comprises the amino acidsequence of SEQ ID NO: 167.

237. The masked cytokine of embodiment 235 or embodiment 236, wherein

king moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 232-234, and 823-825, and the second maskingmoiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 219-229, 261, 826 and 827;

-   -   b) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        219-229, 261, 826 and 827, and the second masking moiety        comprises an amino acid sequence selected from the group        consisting of SEQ ID NOs: 232-234, and 823-825;    -   c) the first masking moiety comprises an amino acid sequence        produced by introducing one or more of the following amino acid        substitutions into the amino acid sequence of any one of SEQ ID        NOs: 232-234, and 823-825: R24A, R26A, K34A, 540A, L42A, and        P67A, and the second masking moiety comprises an amino acid        sequence selected from the group consisting of SEQ ID NOs: 10,        161-165, 219-229, 261, 826 and 827; or    -   d) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        219-229, 261, 826 and 827, and the second masking moiety        comprises an amino acid sequence produced by introducing one or        more of the following amino acid substitutions into the amino        acid sequence of any one of SEQ ID NOs: 232-234, and 823-825:        R24A, R26A, K34A, 540A, L42A, and P67A.

238. The masked cytokine of any one of embodiments 218-237, wherein thefirst half-life extension domain is a first antibody or fragmentthereof, and the second half-life extension domain is a second antibodyor fragment thereof.

239. The masked cytokine of embodiment 238, wherein:

-   -   a) the first antibody or fragment thereof comprises a first        heavy chain polypeptide, and the second antibody or fragment        thereof comprises a second light chain polypeptide; or    -   b) the first antibody or fragment thereof comprises a first        light chain polypeptide, and the second antibody or fragment        thereof comprises a second heavy chain polypeptide.

240. The masked cytokine of embodiment 239, wherein the first heavychain polypeptide, or the second heavy chain polypeptide comprises oneor more amino acid substitutions altering effector function.

241. The masked cytokine of embodiment 240, wherein the first heavychain polypeptide or the second heavy chain polypeptide:

-   -   a) is an IgG1 isotype and comprises the amino substitution(s):        -   i) N297A, N297G, or N297Q;        -   ii) L234A and L235A;            -   C220S, C226S, C229S, and P238S;        -   iv) C226S, C229S, E233P, L234V, and L235A;        -   v) L234F, L235E, and P331S;        -   vi) S267E and L328F;        -   vii) D265A;        -   viii) L234A, L235A, and P329G;    -   b) is an IgG2 isotype and comprises the amino acid        substitution(s):        -   i) V234A and G237A;        -   ii) H268Q, V309L, A330S, and A331S; or        -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or    -   e) is an IgG4 isotype and comprises the amino acid        substitution(s):        -   i) L235A, G237A, and E318A;        -   ii) S228P, L234A, and L235A;        -   iii) H268Q, V309L, A330S, and P331S; or        -   iv) S228P and L235A, numbered according to the Kabat EU            numbering system.

242. The masked cytokine of embodiment 240, wherein the first heavychain polypeptide or the second heavy chain polypeptide comprises one ormore amino acid substitutions enhancing effector function.

243. The masked cytokine of embodiment 242, wherein the first heavychain polypeptide or the second heavy chain polypeptide is an IgG1 heavychain polypeptide and comprises the amino acid substitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;        -   K290E, S298G, and T299A;            -   S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;    -   p) K290N, S298G, T299A, and K326E;    -   q) K334V;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and 1332N;    -   av) S239D and 1332Q;        -   S239E and I332D;            -   and I332N;    -   ay) S239E and I332Q;    -   az) S239N and I332D;    -   ba) S239N and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, I332E, and either S239D or S239N;    -   br) A330L, I332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;        -   E318R;            -   S324I or S324V;    -   cj) K326I or K326T;    -   ck) T335D, T335R, or T335Y;    -   cl) V240I and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

244. The masked cytokine of embodiment 239, wherein the first heavychain polypeptide comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 158, 168, and 169, and the second heavychain polypeptide comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 158, 168, and 169.

245. The masked cytokine of embodiment 239, wherein the first lightchain polypeptide comprises the amino acid sequence of SEQ ID NO: 157 or170, and the second light chain polypeptide comprises the amino acidsequence of SEQ ID NO: 157 or 170.

246. The masked cytokine of embodiment 238, wherein the first antibodyor fragment thereof is a first Fragment crystallizable domain (Fcdomain) or fragment thereof, and the second antibody or fragment thereofis a second Fc domain or fragment thereof.

247. The masked cytokine of embodiment 246, wherein the first Fc domainor fragment thereof, and/or the second Fc domain or fragment thereofcomprises one or more amino acid substitutions altering effectorfunction.

248. The masked cytokine of embodiment 247, wherein the first Fc domainor fragment thereof and/or the second Fc domain or fragment thereof:

-   -   a) is an IgG1 Fc domain or fragment thereof and comprises the        amino substitution(s):        -   i) N297A, N297G, or N297Q;        -   ii) L234A and L235A;        -   iii) C220S, C226S, C229S, and P238S;        -   iv) C226S, C229S, E233P, L234V, and L235A;        -   v) L234F, L235E, and P331S;            -   5267E and L328F;        -   vii) D265A;        -   viii) L234A, L235A, and P329G;    -   b) is an IgG2 Fc domain or fragment thereof and comprises the        amino acid substitution(s):        -   i) V234A and G237A;        -   ii) H268Q, V309L, A330S, and A331S; or        -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or    -   e) is an IgG4 Fc domain or fragment thereof and comprises the        amino acid substitution(s):        -   i) L235A, G237A, and E318A;        -   ii) S228P, L234A, and L235A;        -   iii) H268Q, V309L, A330S, and P331S; or        -   iv) S228P and L235A, numbered according to the Kabat EU            numbering system.

249. The masked cytokine of embodiment 247, wherein first Fc domain orfragment thereof, and/or the second Fc domain or fragment thereofcomprises one or more amino acid substitutions enhancing effectorfunction.

250. The masked cytokine of embodiment 249, wherein the first Fc domainor fragment thereof, and/or the second Fc domain or fragment thereof isan IgG1 Fc domain or fragment thereof and comprises the amino acidsubstitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;    -   m) K290E, S298G, and T299A;    -   n) K290E, S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;        -   K290N, S298G, T299A, and K326E;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and I332N;    -   av) S239D and I332Q;    -   aw) S239E and I332D;    -   ax) S239E and I332N;    -   ay) S239E and I332Q;        -   S239N and I332D;            -   and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, 1332E, and either S239D or S239N;    -   br) A330L, 1332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;    -   ch) E318R;    -   ci) S324D, S324I or S324V;    -   cj) K326I or K326T;        -   T335D, T335R, or T335Y;            -   and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

251. The masked cytokine of embodiment 246, wherein:

-   -   a) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 155, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        156;    -   b) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 156, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        155;    -   c) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 154, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        154;    -   d) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 265, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        156;    -   e) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 156, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        265;    -   f) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 155, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        616;    -   g) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 616, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        155;    -   h) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 157, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        158;    -   i) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 158, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        main or fragment thereof comprises the amino acid sequence of        SEQ ID NO: 796, and the second Fc domain or fragment thereof        comprises the amino acid sequence of SEQ ID NO: 774;    -   k) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 774, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        796;    -   l) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 721, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        619;    -   m) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 619, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        721;    -   n) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 721, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        772;    -   o) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 772, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        721;    -   p) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 793, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        622;    -   q) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 622, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        793;    -   r) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 793, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        773;    -   s) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 773, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        793;    -   t) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 796, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        625;    -   u) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 625, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        omain or fragment thereof comprises the amino acid sequence of        SEQ ID NO: 156, and the second Fc domain or fragment thereof        comprises the amino acid sequence of SEQ ID NO: 156;    -   w) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 796, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        625; or    -   x) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 625, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        796.

252. The masked cytokine of any one of embodiments 218-237, wherein thefirst half-life extension domain is a first scFv or fragment thereof,and the second half-life extension domain is a second scFv or fragmentthereof.

253. The masked cytokine of any one of embodiments 218-237, wherein thefirst half-life extension domain is a first Fc domain or fragmentthereof, and the second half-life extension domain is a second Fc domainor fragment thereof, and wherein the first Fc domain or fragment thereofis linked to the second Fc domain or fragment thereof.

254. The masked cytokine of embodiment 253, wherein the first Fc domainor fragment thereof is linked to the second Fc domain or fragmentthereof via a fourth linker.

255. The masked cytokine of any one of embodiments 218-237, wherein:

-   -   a) the first half-life extension domain is an scFv or fragment        thereof, and the second half-life extension domain is an        antibody or fragment thereof; or    -   a) the first half-life extension domain is an antibody or        fragment thereof, and the second half-life extension domain is        an scFv or fragment thereof.

256. The masked cytokine of any one of embodiments 238-251, wherein themodifications promoting the association of the first and the secondhalf-life extension domain comprise:

-   -   a) introducing S354C and T366W mutations in the first antibody        or fragment thereof, and introducing Y349C, T366S, L368A, and        Y407V mutations in the second antibody or fragment thereof,        numbered according to the Kabat EU numbering system;    -   b) introducing S354C and T366W mutations in the second antibody        or fragment thereof, and introducing Y349C, T366S, L368A, and        Y407V mutations in the first antibody or fragment thereof,        ,rding to the Kabat EU numbering system;        K392D and K409D mutations in the first antibody or fragment        thereof, and introducing D399K and E356K mutations in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   d) introducing K392D and K409D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   e) introducing S364H and F405A mutations in the first antibody        or fragment thereof, and introducing Y349T and T394F mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system; or    -   f) introducing S364H and F405A mutations in the second antibody        or fragment thereof, and introducing Y349T and T394F mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system.

257. The masked cytokine of any one of embodiments 238-251, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing S354C and T366W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349C, T366S,        L368A, and Y407V mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, respectively, numbered according to the Kabat EU        numbering system;    -   b) introducing S354C and T366W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349C, T366S,        L368A, and Y407V mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, respectively, numbered according to the Kabat EU        numbering system;    -   c) introducing K392D and K409D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   d) introducing K392D and K409D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   e) introducing S364H and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349T and        T394F mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system; or    -   f) introducing S364H and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349T and        T394F mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system.        tsked cytokine of any one of embodiments 238-251, wherein the        modifications promoting the association of the first and the        second half-life extension domain comprise:    -   a) introducing a Y407T mutation in the first antibody or        fragment thereof, and introducing a T366Y mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   b) introducing a Y407A mutation in the first antibody or        fragment thereof, and introducing a T366W mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   c) introducing a F405A mutation in the first antibody or        fragment thereof, and introducing a T394W mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   d) introducing a F405W mutation in the first antibody or        fragment thereof, and introducing a T394S mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   e) introducing a Y407T mutation in the first antibody or        fragment thereof, and introducing a T366Y mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   f) introducing T366Y and F405A mutations in the first antibody        or fragment thereof, and introducing T394W and Y407T mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   g) introducing T366W and F405W mutations in the first antibody        or fragment thereof, and introducing T394S and Y407A mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   h) introducing F405W and Y407A mutations in the first antibody        or fragment thereof, and introducing T366W and T394S mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   i) introducing a T366W mutation in the first antibody or        fragment thereof, and introducing T366S, L368A, and Y407V        mutations in the second antibody or fragment thereof, numbered        according to the Kabat EU numbering system;    -   j) introducing a Y407T mutation in the second antibody or        fragment thereof, and introducing a T366Y mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   k) introducing a Y407A mutation in the second antibody or        fragment thereof, and introducing a T366W mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;        -   F405A mutation in the second antibody or fragment thereof,            and introducing a T394W mutation in the first antibody or            fragment thereof, numbered according to the Kabat EU            numbering system;    -   m) introducing a F405W mutation in the second antibody or        fragment thereof, and introducing a T394S mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   n) introducing a Y407T mutation in the second antibody or        fragment thereof, and introducing a T366Y mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   o) introducing T366Y and F405A mutations in the second antibody        or fragment thereof, and introducing T394W and Y407T mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   p) introducing T366W and F405W mutations in the second antibody        or fragment thereof, and introducing T394S and Y407A mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   q) introducing F405W and Y407A mutations in the second antibody        or fragment thereof, and introducing T366W and T394S mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system; or    -   r) introducing a T366W mutation in the second antibody or        fragment thereof, and introducing T366S, L368A, and Y407V        mutations in the first antibody or fragment thereof, numbered        according to the Kabat EU numbering system.

259. The masked cytokine of any one of embodiments 238-251, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   b) introducing a Y407A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   c) introducing a F405A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;        F405W mutation in the amino acid sequence of SEQ ID NO: 154 or        169, and introducing a T394S mutation in the amino acid sequence        of SEQ ID NO: 154 or 169, respectively, numbered according to        the Kabat EU numbering system;    -   e) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   f) introducing T366Y and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394W and        Y407T mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   g) introducing T366W and F405W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394S and        Y407A mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   h) introducing F405W and Y407A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T366W and        T394S mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   i) introducing a T366W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing T366S, L368A, and Y407V        mutations in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   j) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   k) introducing a Y407A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   l) introducing a F405A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   m) introducing a F405W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394S mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   n) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   o) introducing T366Y and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394W and        Y407T mutations in the amino acid sequence of SEQ ID NO: 154 or        ly, numbered according to the Kabat EU numbering system;        T366W and F405W mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, and introducing T394S and Y407A mutations in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   q) introducing F405W and Y407A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T366W and        T394S mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system; or    -   r) introducing a T366W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing T366S, L368A, and Y407V        mutations in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system.

260. The masked cytokine of any one of embodiments 238-251, wherein themodifications promoting the association of the first and the secondhalf-life extension domain comprise:

-   -   a) introducing a K409E mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   b) introducing a K409E mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   c) introducing a K409D mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   d) introducing a K409D mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   e) introducing a K392E mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   f) introducing a K392E mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   g) introducing a K392D mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   h) introducing a K392D mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        :em;        409D and K360D mutations in the first antibody or fragment        thereof, and introducing D399K and E356K mutations in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   j) introducing K409D and K370D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   k) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K, E356K, and E357K        mutations in the second antibody or fragment thereof, numbered        according to the Kabat EU numbering system;    -   l) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing a D399K mutation in the        second antibody or fragment thereof, numbered according to the        Kabat EU numbering system;    -   m) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K and E356K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   n) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   o) introducing K409D and K370D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   p) introducing a D399K mutation in the first antibody or        fragment thereof, and introducing K409D and K360D mutations in        the second antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   q) introducing K409D and K439D mutations in the first antibody        or fragment thereof, and introducing D399K and E356K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   r) introducing a K409E mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   s) introducing a K409E mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   t) introducing a K409D mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        :em;        K409D mutation in the second antibody or fragment thereof, and        introducing a D399R mutation in the first antibody or fragment        thereof, numbered according to the Kabat EU numbering system;    -   v) introducing a K392E mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   w) introducing a K392E mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   x) introducing a K392D mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   y) introducing a K392D mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   z) introducing K409D and K360D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   aa) introducing K409D and K370D mutations in the second antibody        or fragment thereof, and introducing D399K and E357K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   ab) introducing K409D and K392D mutations in the second antibody        or fragment thereof, and introducing D399K, E356K, and E357K        mutations in the first antibody or fragment thereof, numbered        according to the Kabat EU numbering system;

ac) introducing K409D and K392D mutations in the second antibody orfragment thereof, and introducing a D399K mutation in the first antibodyor fragment thereof, numbered according to the Kabat EU numberingsystem;

ad) introducing K409D and K392D mutations in the second antibody orfragment thereof, and introducing D399K and E356K mutations in the firstantibody or fragment thereof, numbered according to the Kabat EUnumbering system;

ae) introducing K409D and K392D mutations in the second antibody orfragment thereof, and introducing D399K and E357K mutations in the firstantibody or fragment thereof, numbered according to the Kabat EUnumbering system;

af) introducing K409D and K370D mutations in the second antibody orfragment thereof, and introducing D399K and E357K mutations in the firstantibody or fragment thereof, numbered according

J numbering system;

a D399K mutation in the second antibody or fragment thereof, andintroducing K409D and K360D mutations in the first antibody or fragmentthereof, numbered according to the Kabat EU numbering system; or

-   -   ah) introducing K409D and K439D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system.

261. The masked cytokine of any one of embodiments 238-251, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   b) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   c) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   d) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   e) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   f) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   g) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   h) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;        409D and K360D mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, and introducing D399K and E356K mutations in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   j) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   k) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K, E356K,        and E357K mutations in the amino acid sequence of SEQ ID NO: 154        or 169, respectively, numbered according to the Kabat EU        numbering system;    -   l) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing a D399K        mutation in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   m) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   n) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   o) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   p) introducing a D399K mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing K409D and K360D mutations        in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   q) introducing K409D and K439D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   r) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   s) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   t) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        ,rding to the Kabat EU numbering system;        K409D mutation in the amino acid sequence of SEQ ID NO: 154 or        169, and introducing a D399R mutation in the amino acid sequence        of SEQ ID NO: 154 or 169, respectively, numbered according to        the Kabat EU numbering system;    -   v) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   w) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   x) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   y) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   z) introducing K409D and K360D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   aa) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   ab) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K, E356K,        and E357K mutations in the amino acid sequence of SEQ ID NO: 154        or 169, respectively, numbered according to the Kabat EU        numbering system;    -   ac) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing a D399K        mutation in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   ad) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, numbered according to the Kabat EU numbering system;    -   ae) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   af) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        -   ly, numbered according to the Kabat EU numbering system;            -   a D399K mutation in the amino acid sequence of SEQ ID                NO: 154 or 169, and introducing K409D and K360D                mutations in the amino acid sequence of SEQ ID NO: 154                or 169, respectively, numbered according to the Kabat EU                numbering system; or    -   ah) introducing K409D and K439D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system.

262. The masked cytokine of any one of embodiments 219-261, wherein thefirst linker comprises a first cleavable peptide; and/or wherein thesecond linker comprises a second cleavable peptide.

263. The masked cytokine of any one of embodiments 219-262, wherein thefirst linker comprises a first N-terminal spacer domain, and/or a firstC-terminal spacer domain.

264. The masked cytokine of embodiment 263, wherein the first linkercomprises:

-   -   a) the first N-terminal spacer domain, the first cleavable        peptide, and the first C-terminal spacer domain;    -   b) the first N-terminal spacer domain and the first cleavable        peptide;    -   c) the first N-terminal spacer domain and the first C-terminal        spacer domain;    -   d) the first cleavable peptide and the first C-terminal spacer        domain;    -   e) the first N-terminal spacer domain; or    -   f) the first C-terminal spacer domain.

265. The masked cytokine of any one of embodiments 219-264, wherein thesecond linker comprises a second N-terminal spacer domain, and/or asecond C-terminal spacer domain.

266. The masked cytokine of embodiment 265, wherein the second linkercomprises:

-   -   a) the second N-terminal spacer domain, the second cleavable        peptide, and the second C-terminal spacer domain;    -   b) the second N-terminal spacer domain and the second cleavable        peptide;    -   c) the second N-terminal spacer domain and the second C-terminal        spacer domain;    -   d) the second cleavable peptide and the second C-terminal spacer        domain;    -   e) the second N-terminal spacer domain; or    -   f) the second C-terminal spacer domain        tsked cytokine of any one of embodiments 262-266, wherein the        first cleavable peptide comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 96-153,        236-242, 264, 270-302, 306-317, 342-347, 356-415, 420-491,        494-501, 504-535, and 538-555; and/or wherein the second        cleavable peptide comprises an amino acid sequence selected from        the group consisting of SEQ ID NOs: 96-153, 236-242, 264,        270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535,        and 538-555.

268. The masked cytokine of any one of embodiments 263-267, wherein thefirst N-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799, and/or the first C-terminal spacerdomain comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340,341, 727, 794, and 799.

269. The masked cytokine of any one of embodiments 262-266, wherein thefirst cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

270. The masked cytokine of embodiment 269, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

271. The masked cytokine of any one of embodiments 265-270, wherein thesecond N-terminal spacer domain comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 20-95, 235, 268, 269,303-305, 323-338, 340, 341, 727, 794, and 799, and/or the secondC-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

272. The masked cytokine of any one of embodiments 262-271, wherein thesecond cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

tsked cytokine of embodiment 272, wherein the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555comprises an N-terminus and a C-terminus, and the amino acid sequenceselected from the group consisting of SEQ ID NOs: 236-242 is linked tothe N-terminus or the C-terminus of the amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

274. The masked cytokine of any one of embodiments 218-273, wherein thefirst linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812,and/or the second linker comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320,323-338, 340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and797-812.

275. The masked cytokine of any one of embodiments 219-274, wherein thethird linker comprises a cleavable peptide.

276. The masked cytokine of any one of embodiments 219-275, wherein thethird linker comprises a third N-terminal spacer domain, and/or a thirdC-terminal spacer domain.

277. The masked cytokine of embodiment 276, wherein the third linkercomprises:

-   -   a) the third N-terminal spacer domain, the third cleavable        peptide, and the third C-terminal spacer domain;    -   b) the third N-terminal spacer domain and the third cleavable        peptide;    -   c) the third N-terminal spacer domain and the third C-terminal        spacer domain;    -   d) the third cleavable peptide and the third C-terminal spacer        domain;    -   e) the third N-terminal spacer domain; or    -   f) the third C-terminal spacer domain.

278. The masked cytokine of any one of embodiments 275-277, wherein thethird cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555;and/or wherein the third cleavable peptide comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153,236-242, 264, 270-302, 306-317, 342-347, 356-415, 420-491, 494-501,504-535, and 538-555.

sked cytokine of any one of embodiments 276-278, wherein the thirdN-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799, and/or the third C-terminal spacerdomain comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340,341, 727, 794, and 799.

280. The masked cytokine of any one of embodiments 275-279, wherein thethird cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

281. The masked cytokine of embodiment 280, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

282. The masked cytokine of any one of embodiments 219-281, wherein thethird linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812,and/or the third linker comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320,323-338, 340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and797-812.

283. The masked cytokine of any one of embodiments 254-282, wherein thefourth linker comprises a fourth N-terminal spacer domain, and/or afourth C-terminal spacer domain.

284. The masked cytokine of embodiment 283, wherein the fourthN-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799, and/or the fourth C-terminalspacer domain comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340,341, 727, 794, and 799.

tsked cytokine of any one of embodiments 262-284, wherein the firstcleavable peptide, the second cleavable peptide, and/or the thirdcleavable peptide is a substrate for a protease that is co-localized ina region or a tissue expressing a cytokine receptor.

286. The masked cytokine of embodiment 285, wherein the cytokinereceptor is an IL-2 cytokine receptor or an IL-15 cytokine receptor.

287. The masked cytokine of any one of embodiments 262-286, wherein thefirst cleavable peptide, the second cleavable peptide, and/or the thirdcleavable peptide is cleaved by one or more enzyme selected from thegroup consisting of: ABHD12, ADAM12, ABHD12B, ABHD13, ABHD17A, ADAM19,ADAM20, ADAM21, ADAM28, ADAM30, ADAM33, ADAMS, ABHD17A, ADAMDEC1,ADAMTS1, ADAMTS10, ADAMTS12, ADAMTS13, ADAMTS14, ADAMTS15, ADAMTS16,ADAMTS17, ADAMTS18, ADAMTS19, ADAMTS2, ADAMTS20, ADAMTS3, ADAMTS4,ABHD17B, ADAMTS5, ADAMTS6, ADAMTS7, ADAMTS8, ADAMTS9, ADAMTSL1,ADAMTSL2, ADAMTSL3, ABHD17C, ADAMTSL5, ASTL, BMP1, CELA1, CELA2A,CELA2B, CELA3A, CELA3B, ADAM10, ADAM15, ADAM17, ADAMS, ADAMTS4, CTSE,CTSF, ADAMTSL4, CMA1, CTRB1, CTRC, CTSO, CTRL, CTSA, CTSW, CTSB, CTSC,CTSD, ESP1, CTSG, CTSH, GZMA, GZMB, GZMH, CTSK, GZMM, CTSL, CTSS, CTSV,CTSZ, HTRA4, KLK10, KLK11, KLK13, KLK14, KLK2, KLK4, DPP4, KLK6, KLK7,KLKB1, ECE1, ECE2, ECEL1, MASP2, MEP1A, MEP1B, ELANE, FAP, GZMA, MMP11,GZMK, HGFAC, HPN, HTRA1, MMP11, MMP16, MMP17, MMP19, HTRA2, MMP20,MMP21, HTRA3, HTRA4, KEL, MMP23B, MMP24, MMP25, MMP26, MMP27, MMP28,KLK5, MMP3, MMP7, MMP8, MMP9, LGMN, LNPEP, MASP1, PAPPA, PAPPA2, PCSK1,NAPSA, PCSK5, PCSK6, MME, MMP1, MMP10, PLAT, PLAU, PLG, PRSS1, PRSS12,PRSS2, PRSS21, PRSS3, PRSS33, PRSS4, PRSS55, PRSS57, MMP12, PRSS8,PRSS9, PRTN3, MMP13, MMP14, ST14, TMPRSS10, TMPRSS11A, TMPRSS11D,TMPRSS11E, TMPRSS11F, TMPRSS12, TMPRSS13, MMP15, TMPRSS15, MMP2,TMPRSS2, TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS6, TMPRSS7, TMPRSS9, NRDC,OVCH1, PAMR1, PCSK3, PHEX, TINAG, TPSAB1, TPSD1, and TPSG1.

288. The masked cytokine of any one of embodiments 218-287, wherein thefirst half-life extension domain and/or the second half-life extensiondomain is conjugated to an agent.

289. The masked cytokine of embodiment 288, wherein the agent is aninhibitor of tubulin polymerization, a DNA damaging agent, or a DNAsynthesis inhibitor.

tsked cytokine of embodiment 289, wherein the agent is a maytansinoid,an auristatin, a pyrrolobenzodiazepine (PBD) dimer, a calicheamicin, aduocarmycin, a indo-linobenzodiazepine dimer or exatecan derivative Dxd.

291. The masked cytokine of embodiment 288, wherein the agent is animmune stimulant.

292. The masked cytokine of embodiment 291, wherein the immune stimulantis a stimulator of interferon genes (STING) agonist or a toll-likereceptor (TLR) agonist.

293. The masked cytokine of embodiment 292, wherein the STING agonist isa cyclic dinucleotide (CDN).

294. The masked cytokine of embodiment 293, wherein the CDN is selectedfrom the group consisting of cGAMP, c-di-AMP, c-di-GMP, cAIMP, c-di-IMP,4-(2-chloro-6-fluorobenzyl)-N-(furan-2-ylmethyl)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamide.

295. The masked cytokine of embodiment 292, wherein the TLR agonist isan agonist of a TLR selected from the group consisting of TLR1, TLR2,TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, and TLR10.

296. A nucleic acid encoding the masked cytokine of any one ofembodiments 1-295 and 320-409.

297. A vector comprising the nucleic acid of embodiment 296.

298. The vector of embodiment 297, which is an expression vector.

299. A host cell comprising the nucleic acid of embodiment 296.

300. A method of producing a masked cytokine comprising culturing thehost cell of embodiment 299 under a condition that produces the maskedcytokine.

301. The method of embodiment 300, further comprising recovering themasked cytokine produced by the host cell.

302. A masked cytokine produced by the method of embodiment 300 orembodiment 301. position comprising the masked cytokine of any one ofembodiments 1-295 and 320-409.

304. A composition comprising the masked cytokine of embodiment 302.

305. The composition of embodiment 303 or embodiment 304, furthercomprising an anti-inflammatory agent or an anti-cancer agent.

306. The composition of embodiment 305, wherein the anti-cancer agent isselected from the group consisting of a PD-1 inhibitor, an EGFRinhibitor, a HER2 inhibitor, a VEGFR inhibitor, a CTLA-4 inhibitor, aBTLA inhibitor, a B7H4 inhibitor, a B7H3 inhibitor, a CSFIR inhibitor,an HVEM inhibitor, a CD27 inhibitor, a KIR inhibitor, an NKG2Ainhibitor, an NKG2D agonist, a TWEAK inhibitor, an ALK inhibitor, a CD52targeting antibody, a CCR4 targeting antibody, a PD-L1 inhibitor, a KITinhibitor, a PDGFR inhibitor, a BAFF inhibitor, an HDAC inhibitor, aVEGF ligand inhibitor, a CD19 targeting molecule, a FOLR1 targetingmolecule, a DLL3 targeting molecule, a DKK1 targeting molecule, a MUC1targeting molecule, a MUC16 targeting molecule, a PSMA targetingmolecule, an MSLN targeting molecule, an NY-ESO-1 targeting molecule, aB7H3 targeting molecule, a B7H4 targeting molecule, a BCMA targetingmolecule, a CD29 targeting molecule, a CD151 targeting molecule, a CD123targeting molecule, a CD33 targeting molecule, a CD37 targetingmolecule, a CDH19 targeting molecule, a CEA targeting molecule, aClaudin 18.2 targeting molecule, a CLEC12A targeting molecule, anEGFRVIII targeting molecule, an EPCAM targeting molecule, an EPHA2targeting molecule, an FCRH5 targeting molecule, an FLT3 targetingmolecule, a GD2 targeting molecule, a glypican 3 targeting molecule, agpA33 targeting molecule, a GPRCSD targeting molecule, an IL-23Rtargeting molecule, an IL-1RAP targeting molecule, a MCSP targetingmolecule, a RON targeting molecule, a ROR1 targeting molecule, a STEAP2targeting molecule, a TfR targeting molecule, a CD166 targetingmolecule, a TPBG targeting molecule, a TROP2 targeting molecule, aproteasome inhibitor, an ABL inhibitor, a CD30 inhibitor, a FLT3inhibitor, a MET inhibitor, a RET inhibitor, an IL-113 inhibitor, a MEKinhibitor, a ROS1 inhibitor, a BRAF inhibitor, a CD38 inhibitor, a RANKLinhibitor, a B4GALNT1 inhibitor, a SLAMF7 inhibitor, an IDH2 inhibitor,an mTOR inhibitor, a CD20 targeting antibody, a BTK inhibitor, a PI3Kinhibitor, a FLT3 inhibitor, a PARP inhibitor, a CDK4 inhibitor, a CDK6inhibitor, an FGFR inhibitor, a RAF inhibitor, a JAK1 inhibitor, a JAK2inhibitor, a JAK3 inhibitor, an IL-6 inhibitor, a IL-17 inhibitor, aSmoothened inhibitor, an IL-6R inhibitor, a BCL2 inhibitor, a PTCHinhibitor, a PIGF inhibitor, a TGFB inhibitor, a CD28 agonist, a CD3agonist, CD40 agonist, a GITR agonist, a OX40 agonist, a VISTA agonist,a CD137 agonist, a LAG3 inhibitor, a TIM3 inhibitor, a TIGIT inhibitor,and an IL-2R inhibitor.

mposition of embodiment 305, wherein the anti-inflammatory agent is acyclooxygenase (COX) inhibitor or an NF-κB inhibitor.

308. The composition of embodiment 307, wherein the COX inhibitor is aCOX-1 and/or COX-2 inhibitor.

309. The composition of embodiment 307 or embodiment 308, wherein theCOX inhibitor is selected from the group consisting of SC-560, FR122047,P6, mofezolac, TFAP, flurbiprofen, ketoprofen, celecoxib, rofecoxib,meloxicam, piroxicam, deracoxib, parecoxib, valdecoxib, etoricoxib, achromene derivative, a chroman derivative,N-(2-cyclohexyloxynitrophenyl) methane sulfonamide, parecoxib,lumiracoxib, RS 57067, T-614, BMS-347070, JTE-522, S-2474, SVT-2016,CT-3, ABT-963, SC-58125, nimesulide, flosulide, NS-398, L-745337,RWJ-63556, L-784512, darbufelone, CS-502, LAS-34475, LAS-34555, S-33516,diclofenac, mefenamic acid, SD-8381, ibuprofen, naproxen, ketorolac,indomethacin, aspirin, naproxen, tolmetin, piroxicam, and meclofenamate.

310. The composition of embodiment 307, wherein the NF-κB inhibitor isselected from the group consisting of an IKK complex inhibitor, an IκBdegradation inhibitor, an NF-κB nuclear translocation inhibitor, a p65acetylation inhibitor, an NF-κB DNA binding inhibitor, an NF-κBtransactivation inhibitor, and a p53 induction inhibitor.

311. The composition of embodiment 307 or embodiment 308, wherein theNF-κB inhibitor is selected from the group consisting of TPCA-1, NF-κBActivation Inhibitor VI (BOT-64), BMS-345541, amlexanox, SC-514(GK-01140), IMD-0354, IKK-16, BAY-11-7082, MG-115, MG-132, lactacystin,epoxomicin, parthenolide, carfilzomib, MLN-4924 (pevonedistat), JSH-23rolipram, gallic acid, anacardic acid, GYY-4137, p-XSC, CV-3988,prostaglandin E2 (PGE2), LY-294002, wortmannin, mesalamine, quinacrine,and flavopiridol.

312. A pharmaceutical composition comprising the masked cytokine of anyone of embodiments 1-295 and 320-409, and a pharmaceutically acceptablecarrier.

313. A pharmaceutical composition comprising the masked cytokine ofembodiment 302, and a pharmaceutically acceptable carrier.

314. A kit comprising the masked cytokine of any one of embodiments1-295 and 320-409, or the composition of any one of embodiments 303-311,or the pharmaceutical composition of embodiment 312 or 313.

Lod of treating or preventing a neoplastic disease in a subject, themethod comprising administering to the subject an effective amount ofthe masked cytokine of any one of embodiments 1-295 and 320-409, or thecomposition of any one of embodiments 303-311.

316. The method of embodiment 315, wherein the neoplastic disease is acancer.

317. The method of embodiment 316, wherein the cancer is leukemia,lymphoma, head and neck cancer, colorectal cancer, prostate cancer,pancreatic cancer, melanoma, breast cancer, neuroblastoma, lung cancer,ovarian cancer, osteosarcoma, bladder cancer, cervical cancer, livercancer, kidney cancer, skin cancer or testicular cancer.

318. A method of treating or preventing an inflammatory or autoimmunedisease in a subject, the method comprising administering to the subjectan effective amount of the masked cytokine of any one of embodiments1-295 and 320-409, or the composition of any one of embodiments 303-311.

319. The method of embodiment 318, wherein the inflammatory orautoimmune disease is selected from the group consisting ofatherosclerosis, obesity, inflammatory bowel disease (IBD), rheumatoidarthritis, allergic encephalitis, psoriasis, atopic skin disease,osteoporosis, peritonitis, hepatitis, lupus, celiac disease, Sjogren'ssyndrome, polymyalgia rheumatica, multiple sclerosis (MS), ankylosingspondylitis, type 1 diabetes mellitus, alopecia areata, vasculitis, andtemporal arteritis, graft versus host disease (GVHD), asthma, COPD, aparaneoplastic autoimmune disease, cartilage inflammation, juvenilearthritis, juvenile rheumatoid arthritis, pauciarticular juvenilerheumatoid arthritis, polyarticular juvenile rheumatoid arthritis,systemic onset juvenile rheumatoid arthritis, juvenile ankylosingspondylitis, juvenile enteropathic arthritis, juvenile reactivearthritis, juvenile Reiter's Syndrome, SEA Syndrome (Seronegativity,Enthesopathy, Arthropathy Syndrome), juvenile dermatomyositis, juvenilepsoriatic arthritis, juvenile Scleroderma, juvenile systemic lupuserythematosus, juvenile vasculitis, pauciarticular rheumatoid arthritis,systemic onset rheumatoid arthritis, enteropathic arthritis, reactivearthritis, Reiter's Syndrome, dermatomyositis, psoriatic arthritis,Scleroderma, vasculitis, myolitis, polymyolitis, dermatomyolitis,polyarteritis nodossa, Wegener's granulomatosis, arteritis, ploymyalgiarheumatica, sarcoidosis, Sclerosis, primary biliary Sclerosis,Sclerosing cholangitis, psoriasis, plaque psoriasis, guttate psoriasis,inverse psoriasis, pustular psoriasis, erythrodermic psoriasis,dermatitis, atopic dermatitis, atherosclerosis, Still's disease,Systemic Lupus Erythematosus (SLE), myasthenia gravis, Crohn's disease,ulcerative colitis, celiac disease, rhinosinusitis, rhinosinusitis withpolyps, eosinophilic esophogitis, eosinophilic bronchitis,Guillain-Barre disease, thyroiditis (e.g., Graves'disease), Addison'sdisease, Raynaud's phenomenon, autoimmune

31antation rejection, kidney damage, hepatitis C-induced vasculitis, andspontaneous loss

ced cytokine comprising:

-   -   a) a first half-life extension domain comprising the amino acid        sequence of SEQ ID NO: 155, and a second half-life extension        domain comprising the amino acid sequence of SEQ ID NO: 156;    -   b) a masking moiety comprising the amino acid sequence of SEQ ID        NO: 261; and    -   c) a cytokine or functional fragment thereof comprising the        amino acid sequence of SEQ ID NO: 3,    -   wherein the masking moiety is linked to the first half-life        extension domain,    -   wherein the cytokine or functional fragment thereof is linked to        the second half-life extension domain, and    -   wherein the first half-life extension domain and the second        half-life extension domain contain modifications promoting the        association of the first and the second half-life extension        domain.

321. The masked cytokine of embodiment 320, wherein the masking moietyis linked to the first half-life extension domain via a first linker,and wherein the cytokine or functional fragment thereof is linked to thesecond half-life extension domain via a second linker.

322. The masked cytokine of embodiment 321, wherein the first linkercomprises the amino acid sequence of SEQ ID NO: 28.

323. The masked cytokine of embodiment 321 or embodiment 322, whereinthe second linker comprises a cleavable peptide comprising the aminoacid sequence of SEQ ID NO: 264.

324. The masked cytokine of any one of embodiments 321-323, wherein thesecond linker comprises the amino acid sequence of SEQ ID NO: 811.

325. The masked cytokine of any one of embodiments 320-324, wherein themasked cytokine comprises the amino acid sequence of SEQ ID NO: 266.

326. The masked cytokine of any one of embodiments 320-325, wherein themasked cytokine comprises the amino acid sequence of SEQ ID NO: 267.

327. The masked cytokine of any one of embodiments 320-326, wherein themasked cytokine comprises the amino acid sequences of SEQ ID NOs: 266and 267.

tsked cytokine of embodiment 1, wherein the masked cytokine comprises anamino acid sequence selected from the group consisting of SEQ ID NOs:585-597, 602, 610-614, 627-636, 642, and 643.

329. The masked cytokine of embodiment 70, wherein the masked cytokinecomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 567 and 598-601.

330. The masked cytokine of embodiment 149, wherein the masked cytokinecomprises the amino acid sequences of: SEQ ID NOs: 562 and 563; or SEQID NOs: 608 and 603; or SEQ ID NOs: 604 and 603; or SEQ ID NOs: 605 and603; or SEQ ID NOs: 606 and 603; or SEQ ID NOs: 615 and 617; or SEQ IDNOs: 266 and 267; or SEQ ID NOs: 618 and 620; or SEQ ID NOs: 621 and623; or SEQ ID NOs: 624 and 626; or SEQ ID NOs: 608 and 267; or SEQ IDNOs: 663 and 664; or SEQ ID NOs: 665 and 666; or SEQ ID NOs: 667 and267; or SEQ ID NOs: 669 and 267; or SEQ ID NOs: 670 and 671; or SEQ IDNOs: 670 and 671; or SEQ ID NOs: 672 and 267; or SEQ ID NOs: 673 and267; or SEQ ID NOs: 674 and 267; or SEQ ID NOs: 675 and 267; or SEQ IDNOs: 676 and 267; or SEQ ID NOs: 677 and 267; or SEQ ID NOs: 678 and267; or SEQ ID NOs: 679 and 267; or SEQ ID NOs: 680 and 267; or SEQ IDNOs: 681 and 267; or SEQ ID NOs: 682 and 267; or SEQ ID NOs: 683 and267; or SEQ ID NOs: 684 and 267; or SEQ ID NOs: 685 and 267; or SEQ IDNOs: 686 and 267; SEQ ID NOs: 687 and 267; or SEQ ID NOs: 688 and 267;or SEQ ID NOs: 689 and 267; or SEQ ID NOs: 690 and 267; or SEQ ID NOs:692 and 267; or SEQ ID NOs: 693 and 267; or SEQ ID NOs: 694 and 267; orSEQ ID NOs: 695 and 267; or SEQ ID NOs: 696 and 267; or SEQ ID NOs: 697and 267; or SEQ ID NOs: 698 and 267; or SEQ ID NOs: 699 and 267; or SEQID NOs: 700 and 267; or SEQ ID NOs: 701 and 267; or SEQ ID NOs: 702 and267; or SEQ ID NOs: 703 and 267; or SEQ ID NOs: 704 and 267; or SEQ IDNOs: 705 and 267; or SEQ ID NOs: 706 and 267; or SEQ ID NOs: 707 and267; or SEQ ID NOs: 708 and 267; or SEQ ID NOs: 709 and 267; or SEQ IDNOs: 710 and 267; or SEQ ID NOs: 711 and 267; or SEQ ID NOs: 712 and667; or SEQ ID NOs: 713 and 267; or SEQ ID NOs: 714 and 267; or SEQ IDNOs: 716 and 699; or SEQ ID NOs: 717 and 267; or SEQ ID NOs: 718 and267; or SEQ ID NOs: 719 and 267; or SEQ ID NOs: 720 and 267; or SEQ IDNOs: 722 and 267; or SEQ ID NOs: 723 and 267; or SEQ ID NOs: 720 and267; or SEQ ID NOs: 728 and 267; or SEQ ID NOs: 729 and 267; or SEQ IDNOs: 730 and 267; or SEQ ID NOs: 731 and 267; or SEQ ID NOs: 732 and267; or SEQ ID NOs: 733 and 267; or SEQ ID NOs: 734 and 267; or SEQ IDNOs: 735 and 267; or SEQ ID NOs: 736 and 267; or SEQ ID NOs: 737 and267; or SEQ ID NOs: 738 and 267; or SEQ ID NOs: 739 and 267; or SEQ IDNOs: 740 and 267; or SEQ ID NOs: 741 and 267; or SEQ ID NOs: 742 and267; or SEQ ID NOs: 743 and 267; or SEQ ID NOs: 744 and 267; or SEQ IDNOs: 745 and 267; or SEQ ID NOs: 746 and 267; or SEQ ID NOs: 674 and828; or SEQ ID NOs: 674 and 829; or SEQ ID NOs: 726 and 830; or SEQ IDNOs: 726

-   -   Q ID NOs: 747 and 671; or SEQ ID NOs: 715 and 267; or SEQ ID        NOs: 715 and 671; or 571; or SEQ ID NOs: 749 and 671; or SEQ ID        NOs: 750 and 671; or SEQ ID NOs: 751 and 671; or SEQ ID NOs: 752        and 671; or SEQ ID NOs: 753 and 671; or SEQ ID NOs: 754 and 671;        or SEQ ID NOs: 758 and 671; or SEQ ID NOs: 759 and 671; or SEQ        ID NOs: 760 and 671; or SEQ ID NOs: 761 and 671.

331. The masked cytokine of embodiment 218, wherein the masked cytokinecomprises the amino acid sequences of: SEQ ID NOs: 755 and 616; or SEQID NOs: 756 and 616; or SEQ ID NOs: 757 and 616.

332. A masked cytokine comprising:

-   -   a) a first half-life extension domain and a second half-life        extension domain;    -   b) a first masking moiety and a second masking moiety; and    -   c) a cytokine or functional fragment thereof,    -   wherein the first masking moiety is linked to the first        half-life extension domain,    -   wherein the second masking moiety is linked to the first masking        moiety,    -   wherein the cytokine or functional fragment thereof is linked to        the second half-life extension domain, and    -   wherein the first half-life extension domain and the second        half-life extension domain contain modifications promoting the        association of the first and the second half-life extension        domain.

333. The masked cytokine of embodiment 332, wherein:

-   -   a) the first masking moiety is linked to the first half-life        extension domain via a first linker; and/or    -   b) the second masking moiety is linked to the first masking        moiety via a second linker.

334. The masked cytokine of embodiment 332 or 333, wherein the cytokineor functional fragment thereof is linked to the second half-lifeextension domain via a third linker.

335. The masked cytokine of any one of embodiments 332-334, wherein thecytokine or functional fragment thereof is an IL-2 polypeptide orfunctional fragment thereof.

336. The masked cytokine of embodiment 335, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 1-8, 160, 243-251, 230,243-251, 260, 775-792, and 813-822.

-   -   tsked cytokine of embodiment 335, wherein the IL-2 polypeptide        or functional fragment thereof comprises an amino acid sequence        produced by introducing one or more amino acid substitutions        into the amino acid sequence of the IL-2 polypeptide or        functional fragment thereof that reduces the affinity of the        IL-2 polypeptide or functional fragment thereof for CD25        (IL-2Rα).

338. The masked cytokine of embodiment 337, wherein the amino acidsequence is produced by introducing one or more of the following aminoacid substitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: R38A, F42A, F42K, F42E, K43A, Y45A, Y45N, Y45R,E62A, E62R, E62S, and L72G.

339. The masked cytokine of embodiment 335, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby introducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatincreases the affinity of the IL-2 polypeptide or functional fragmentthereof for IL-2Rβ or IL-2Rγ.

340. The masked cytokine of embodiment 339, wherein the amino acidsequence is produced by introducing one or more of the following aminoacid substitutions into any one of SEQ ID NOs: 1-8, 160, 243-251, 260,775-792, and 813-822: H161, L18C, D20A, D20L, D20F, N29L, L80F, R81D,L85V, I86V, and I92F.

341. The masked cytokine of embodiment 337 or embodiment 338, whereinthe amino acid sequence is produced by further introducing one or moreamino acid substitutions that increase the affinity of the IL-2polypeptide or functional fragment thereof for IL-2Rβ or IL-2Rγ.

342. The masked cytokine of embodiment 341, wherein the one or moreamino acid substitutions that increase the affinity of the IL-2polypeptide or functional fragment thereof for IL-2Rβ or IL-2Rγ isselected from the group consisting of H161, L18C, D20A, D20L, D20F,N29L, L80F, R81D, L85V, I86V, and I92F.

343. The masked cytokine of embodiment 335, wherein the IL-2 polypeptideor functional fragment thereof comprises an amino acid sequence producedby introducing one or more amino acid substitutions into the amino acidsequence of the IL-2 polypeptide or functional fragment thereof thatstabilizes the IL-2 polypeptide or functional fragment thereof.

-   -   tsked cytokine of embodiment 343, wherein the amino acid        sequence is produced by introducing one of the following amino        acid substitutions into any one of SEQ ID NOs: 1-8, 160,        243-251, 260, 775-792, and 813-822: C125S, C125A, and C125G.

345. The masked cytokine of any one of embodiments 337-342, wherein theamino acid sequence is produced by further introducing one or more aminoacid substitutions that stabilize the IL-2 polypeptide or functionalfragment thereof.

346. The masked cytokine of embodiment 345, wherein the one or moreamino acid substitutions that stabilize the IL-2 polypeptide orfunctional fragment thereof is the amino acid substitution C125S, C125A,or C125G.

347. The masked cytokine of any one of embodiments 335-346, wherein thefirst masking moiety comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 9, 10, 161-165, 187-218, 221-229, 231,261, 826 and 827 and the second masking moiety comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 9, 10,161-165, 187-218, 221-229, 231, 261, 826 and 827 and wherein the aminoacid sequence of the first masking moiety and the second masking moietyare different.

348. The masked cytokine of any one of embodiments 335-347, wherein:

-   -   a) the first masking moiety comprises the amino acid sequence of        SEQ ID NO: 9 or 231, and the second masking moiety comprises an        amino acid sequence selected from the group consisting of SEQ ID        NOs: 10, 161-165, 187-218, 221-226, 261, 826 and 827; or    -   b) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        187-218, 221-226, 261, 826 and 827, and the second masking        moiety comprises the amino acid sequence of SEQ ID NO: 9 or 231.

349. The masked cytokine of any one of embodiments 332-334, wherein thecytokine or functional fragment thereof is an IL-15 polypeptide orfunctional fragment thereof.

350. The masked cytokine of embodiment 349, wherein the IL-15polypeptide or functional fragment thereof comprises the amino acidsequence of SEQ ID NO: 167.

351. The masked cytokine of embodiment 349 or embodiment 350, wherein

-   -   king moiety comprises an amino acid sequence selected from the        group consisting of SEQ ID NOs: 232-234, and 823-825, and the        second masking moiety comprises an amino acid sequence selected        from the group consisting of SEQ ID NOs: 10, 161-165, 219-229,        261, 826 and 827;    -   b) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        219-229, 261, 826 and 827, and the second masking moiety        comprises an amino acid sequence selected from the group        consisting of SEQ ID NOs: 232-234, and 823-825;    -   c) the first masking moiety comprises an amino acid sequence        produced by introducing one or more of the following amino acid        substitutions into the amino acid sequence of any one of SEQ ID        NOs: 232-234, and 823-825: R24A, R26A, K34A, 540A, L42A, and        P67A, and the second masking moiety comprises an amino acid        sequence selected from the group consisting of SEQ ID NOs: 10,        161-165, 219-229, 261, 826 and 827; or    -   d) the first masking moiety comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 10, 161-165,        219-229, 261, 826 and 827, and the second masking moiety        comprises an amino acid sequence produced by introducing one or        more of the following amino acid substitutions into the amino        acid sequence of any one of SEQ ID NOs: 232-234, and 823-825:        R24A, R26A, K34A, 540A, L42A, and P67A.

352. The masked cytokine of any one of embodiments 332-351, wherein thefirst half-life extension domain is a first antibody or fragmentthereof, and the second half-life extension domain is a second antibodyor fragment thereof.

353. The masked cytokine of embodiment 352, wherein:

-   -   a) the first antibody or fragment thereof comprises a first        heavy chain polypeptide, and the second antibody or fragment        thereof comprises a second light chain polypeptide; or    -   b) the first antibody or fragment thereof comprises a first        light chain polypeptide, and the second antibody or fragment        thereof comprises a second heavy chain polypeptide.

354. The masked cytokine of embodiment 353, wherein the first heavychain polypeptide, or the second heavy chain polypeptide comprises oneor more amino acid substitutions altering effector function.

355. The masked cytokine of embodiment 354, wherein the first heavychain polypeptide or the second heavy chain polypeptide:

-   -   a) is an IgG1 isotype and comprises the amino substitution(s):        -   i) N297A, N297G, or N297Q;        -   ii) L234A and L235A;            -   C220S, C226S, C229S, and P238S;        -   iv) C226S, C229S, E233P, L234V, and L235A;        -   v) L234F, L235E, and P331S;        -   vi) S267E and L328F;        -   vii) D265A;        -   viii) L234A, L235A, and P329G;    -   b) is an IgG2 isotype and comprises the amino acid        substitution(s):        -   i) V234A and G237A;        -   ii) H268Q, V309L, A330S, and A331S; or    -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or    -   e) is an IgG4 isotype and comprises the amino acid        substitution(s):        -   i) L235A, G237A, and E318A;        -   ii) S228P, L234A, and L235A;        -   iii) H268Q, V309L, A330S, and P331S; or        -   iv) S228P and L235A, numbered according to the Kabat EU            numbering system.

356. The masked cytokine of embodiment 353, wherein the first heavychain polypeptide or the second heavy chain polypeptide comprises one ormore amino acid substitutions enhancing effector function.

357. The masked cytokine of embodiment 356, wherein the first heavychain polypeptide or the second heavy chain polypeptide is an IgG1 heavychain polypeptide and comprises the amino acid substitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;        -   K290E, S298G, and T299A;            -   S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;    -   p) K290N, S298G, T299A, and K326E;    -   q) K334V;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and 1332N;    -   av) S239D and 1332Q;        -   S239E and I332D;            -   and I332N;    -   ay) S239E and I332Q;    -   az) S239N and I332D;    -   ba) S239N and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, 1332E, and either S239D or S239N;    -   br) A330L, 1332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;        -   E318R;            -   S324I or S324V;    -   cj) K326I or K326T;    -   ck) T335D, T335R, or T335Y;    -   cl) V240I and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

358. The masked cytokine of embodiment 353, wherein the first heavychain polypeptide comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 158, 168, and 169, and the second heavychain polypeptide comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 158, 168, and 169.

359. The masked cytokine of embodiment 353, wherein the first lightchain polypeptide comprises the amino acid sequence of SEQ ID NO: 157 or170, and the second light chain polypeptide comprises the amino acidsequence of SEQ ID NO: 157 or 170.

360. The masked cytokine of embodiment 352, wherein the first antibodyor fragment thereof is a first Fragment crystallizable domain (Fcdomain) or fragment thereof, and the second antibody or fragment thereofis a second Fc domain or fragment thereof.

361. The masked cytokine of embodiment 360, wherein the first Fc domainor fragment thereof, and/or the second Fc domain or fragment thereofcomprises one or more amino acid substitutions altering effectorfunction.

362. The masked cytokine of embodiment 361, wherein the first Fc domainor fragment thereof and/or the second Fc domain or fragment thereof:

-   -   a) is an IgG1 Fc domain or fragment thereof and comprises the        amino substitution(s):        -   i) N297A, N297G, or N297Q;        -   ii) L234A and L235A;        -   iii) C220S, C226S, C229S, and P238S;        -   iv) C226S, C229S, E233P, L234V, and L235A;        -   v) L234F, L235E, and P331S;            -   S267E and L328F;        -   vii) D265A;        -   viii) L234A, L235A, and P329G;    -   b) is an IgG2 Fc domain or fragment thereof and comprises the        amino acid substitution(s):        -   i) V234A and G237A;        -   ii) H268Q, V309L, A330S, and A331S; or        -   iii) V234A, G237A, P238S, H268A, V309L, A330S, and P331S; or    -   e) is an IgG4 Fc domain or fragment thereof and comprises the        amino acid substitution(s):        -   i) L235A, G237A, and E318A;        -   ii) S228P, L234A, and L235A;        -   iii) H268Q, V309L, A330S, and P331S; or    -   iv) S228P and L235A, numbered according to the Kabat EU        numbering system.

363. The masked cytokine of embodiment 361, wherein the first Fc domainor fragment thereof and/or the second Fc domain or fragment thereofcomprises one or more amino acid substitutions enhancing effectorfunction.

364. The masked cytokine of embodiment 363, wherein the first Fc domainor fragment thereof and/or the second Fc domain or fragment thereof isan IgG1 Fc domain or fragment thereof and comprises the amino acidsubstitution(s):

-   -   a) S298A, E333A, and K334A;    -   b) S239D and I332E;    -   c) S239D, A330L, and I332E;    -   d) P247I and A339D or A339Q;    -   e) D280H and K290S;    -   f) D280H, K290S, and either S298D or S298V;    -   g) F243L, R292P, and Y300L;    -   h) F243L, R292P, Y300L, and P396L;    -   i) F243L, R292P, Y300L, V305I, and P396L;    -   j) G236A, S239D, and I332E;    -   k) K326A and E333A;    -   l) K326W and E333S;    -   m) K290E, S298G, and T299A;    -   n) K290E, S298G, T299A, and K326E;    -   o) K290N, S298G, and T299A;        -   K290N, S298G, T299A, and K326E;    -   r) L235S, S239D, and K334V;    -   s) K334V and Q331M, S239D, F243V, E294L, or S298T;    -   t) E233L, Q311M, and K334V;    -   u) L234I, Q311M, and K334V;    -   v) K334V and S298T, A330M, or A330F;    -   w) K334V, Q311M, and either A330M or A330F;    -   x) K334V, S298T, and either A330M or A330F;    -   y) K334V, S239D, and either A330M or S298T;    -   z) L234Y, Y296W, and K290Y, F243V, or E294L;    -   aa) Y296W and either L234Y or K290Y;    -   ab) S239D, A330S, and I332E,    -   ac) V264I;    -   ad) F243L and V264I;    -   ae) L328M;    -   af) I332E;    -   ag) L328M and I332E;    -   ah) V264I and I332E;    -   ai) S239E and I332E;    -   aj) S239Q and I332E;    -   ak) S239E;    -   al) A330Y;    -   am) I332D;    -   an) L328I and I332E;    -   ao) L328Q and I332E;    -   ap) V264T;    -   aq) V240I;    -   ar) V266I;    -   as) S239D;    -   at) S239D and I332D;    -   au) S239D and I332N;    -   av) S239D and I332Q;    -   aw) S239E and I332D;    -   ax) S239E and I332N;    -   ay) S239E and I332Q;        -   S239N and I332D;            -   and I332E;    -   bb) S239Q and I332D;    -   bc) A330Y and I332E;    -   bd) V264I, A330Y, and I332E;    -   be) A330L and I332E;    -   bf) V264I, A330L, and I332E;    -   bg) L234E, L234Y, or L234I;    -   bh) L235D, L235S, L235Y, or L235I;    -   bi) S239T;    -   bj) V240M;    -   bk) V264Y;    -   bl) A330I;    -   bm) N325T;    -   bn) I332E and L328D, L328V, L328T, or L328I;    -   bo) V264I, I332E, and either S239E or S239Q;    -   bp) S239E, V264I, A330Y, and I332E;    -   bq) A330Y, 1332E, and either S239D or S239N;    -   br) A330L, 1332E, and either S239D or S239N;    -   bs) V264I, S298A, and I332E;    -   bt) S298A, I332E, and either S239D or S239N;    -   bu) S239D, V264I, and I332E;    -   by) S239D, V264I, S298A, and I332E;    -   bw) S239D, V264I, A330L, and I332E;    -   bx) S239D, I332E, and A330I;    -   by) P230A;    -   bz) P230A, E233D, and I332E;    -   ca) E272Y;    -   cb) K274T, K274E, K274R, K274L, or K274Y;    -   cd) F275W;    -   ce) N276L;    -   cf) Y278T;    -   cg) V302I;    -   ch) E318R;    -   ci) S324D, S324I or S324V;    -   cj) K326I or K326T;        -   T335D, T335R, or T335Y;            -   and V266I;    -   cm) S239D, A330Y, I332E, and L234I;    -   cn) S239D, A330Y, I332E, and L235D;    -   co) S239D, A330Y, I332E, and V240I;    -   cp) S239D, A330Y, I332E, and V264T; or    -   cq) S239D, A330Y, I332E, and either K326E or K326T, numbered        according to the Kabat EU numbering system.

365. The masked cytokine of embodiment 360, wherein:

-   -   a) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 155, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        156;    -   b) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 156, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        155;    -   c) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 154, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        154;    -   d) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 265, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        156;    -   e) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 156, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        265;    -   f) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 155, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        616;    -   g) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 616, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        155;    -   h) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 157, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        158;    -   i) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 158, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        main or fragment thereof comprises the amino acid sequence of        SEQ ID NO: 796, and the second Fc domain or fragment thereof        comprises the amino acid sequence of SEQ ID NO: 774;    -   k) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 774, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        796;    -   l) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 721, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        619;    -   m) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 619, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        721;    -   n) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 721, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        772;    -   o) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 772, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        721;    -   p) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 793, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        622;    -   q) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 622, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        793;    -   r) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 793, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        773;    -   s) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 773, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        793;    -   t) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 796, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        625;    -   u) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 625, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        omain or fragment thereof comprises the amino acid sequence of        SEQ ID NO: 156, and the second Fc domain or fragment thereof        comprises the amino acid sequence of SEQ ID NO: 156;    -   w) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 796, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        625; or    -   x) the first Fc domain or fragment thereof comprises the amino        acid sequence of SEQ ID NO: 625, and the second Fc domain or        fragment thereof comprises the amino acid sequence of SEQ ID NO:        796.

366. The masked cytokine of any one of embodiments 332-351, wherein thefirst half-life extension domain is a first scFv or fragment thereof,and the second half-life extension domain is a second scFv or fragmentthereof.

367. The masked cytokine of any one of embodiments 332-351, wherein thefirst half-life extension domain is a first Fc domain or fragmentthereof, and the second half-life extension domain is a second Fc domainor fragment thereof, and wherein the first Fc domain or fragment thereofis linked to the second Fc domain or fragment thereof.

368. The masked cytokine of embodiment 367, wherein the first Fc domainor fragment thereof is linked to the second Fc domain or fragmentthereof via a fourth linker.

369. The masked cytokine of any one of embodiments 232-351, wherein:

-   -   a) the first half-life extension domain is an scFv or fragment        thereof, and the second half-life extension domain is an        antibody or fragment thereof; or    -   a) the first half-life extension domain is an antibody or        fragment thereof, and the second half-life extension domain is        an scFv or fragment thereof.

370. The masked cytokine of any one of embodiments 352-365, wherein themodifications promoting the association of the first and the secondhalf-life extension domain comprise:

-   -   a) introducing S354C and T366W mutations in the first antibody        or fragment thereof, and introducing Y349C, T366S, L368A, and        Y407V mutations in the second antibody or fragment thereof,        numbered according to the Kabat EU numbering system;    -   b) introducing S354C and T366W mutations in the second antibody        or fragment thereof, and introducing Y349C, T366S, L368A, and        Y407V mutations in the first antibody or fragment thereof,        ,rding to the Kabat EU numbering system;        K392D and K409D mutations in the first antibody or fragment        thereof, and introducing D399K and E356K mutations in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   d) introducing K392D and K409D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   e) introducing S364H and F405A mutations in the first antibody        or fragment thereof, and introducing Y349T and T394F mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system; or    -   f) introducing S364H and F405A mutations in the second antibody        or fragment thereof, and introducing Y349T and T394F mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system.

371. The masked cytokine of any one of embodiments 352-365, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing S354C and T366W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349C, T366S,        L368A, and Y407V mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, respectively, numbered according to the Kabat EU        numbering system;    -   b) introducing S354C and T366W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349C, T366S,        L368A, and Y407V mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, respectively, numbered according to the Kabat EU        numbering system;    -   c) introducing K392D and K409D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   d) introducing K392D and K409D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   e) introducing S364H and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349T and        T394F mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system; or    -   f) introducing S364H and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing Y349T and        T394F mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system.        tsked cytokine of any one of embodiments 352-365, wherein the        modifications promoting the association of the first and the        second half-life extension domain comprise:    -   a) introducing a Y407T mutation in the first antibody or        fragment thereof, and introducing a T366Y mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   b) introducing a Y407A mutation in the first antibody or        fragment thereof, and introducing a T366W mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   c) introducing a F405A mutation in the first antibody or        fragment thereof, and introducing a T394W mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   d) introducing a F405W mutation in the first antibody or        fragment thereof, and introducing a T394S mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   e) introducing a Y407T mutation in the first antibody or        fragment thereof, and introducing a T366Y mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   f) introducing T366Y and F405A mutations in the first antibody        or fragment thereof, and introducing T394W and Y407T mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   g) introducing T366W and F405W mutations in the first antibody        or fragment thereof, and introducing T394S and Y407A mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   h) introducing F405W and Y407A mutations in the first antibody        or fragment thereof, and introducing T366W and T394S mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   i) introducing a T366W mutation in the first antibody or        fragment thereof, and introducing T366S, L368A, and Y407V        mutations in the second antibody or fragment thereof, numbered        according to the Kabat EU numbering system;    -   j) introducing a Y407T mutation in the second antibody or        fragment thereof, and introducing a T366Y mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   k) introducing a Y407A mutation in the second antibody or        fragment thereof, and introducing a T366W mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;        F405A mutation in the second antibody or fragment thereof, and        introducing a T394W mutation in the first antibody or fragment        thereof, numbered according to the Kabat EU numbering system;    -   m) introducing a F405W mutation in the second antibody or        fragment thereof, and introducing a T394S mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   n) introducing a Y407T mutation in the second antibody or        fragment thereof, and introducing a T366Y mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   o) introducing T366Y and F405A mutations in the second antibody        or fragment thereof, and introducing T394W and Y407T mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   p) introducing T366W and F405W mutations in the second antibody        or fragment thereof, and introducing T394S and Y407A mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   q) introducing F405W and Y407A mutations in the second antibody        or fragment thereof, and introducing T366W and T394S mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system; or    -   r) introducing a T366W mutation in the second antibody or        fragment thereof, and introducing T366S, L368A, and Y407V        mutations in the first antibody or fragment thereof, numbered        according to the Kabat EU numbering system.

373. The masked cytokine of any one of embodiments 352-365, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   b) introducing a Y407A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   c) introducing a F405A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;        F405W mutation in the amino acid sequence of SEQ ID NO: 154 or        169, and introducing a T394S mutation in the amino acid sequence        of SEQ ID NO: 154 or 169, respectively, numbered according to        the Kabat EU numbering system;    -   e) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   f) introducing T366Y and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394W and        Y407T mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   g) introducing T366W and F405W mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394S and        Y407A mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   h) introducing F405W and Y407A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T366W and        T394S mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   i) introducing a T366W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing T366S, L368A, and Y407V        mutations in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   j) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   k) introducing a Y407A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   l) introducing a F405A mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394W mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   m) introducing a F405W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T394S mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   n) introducing a Y407T mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a T366Y mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   o) introducing T366Y and F405A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T394W and        Y407T mutations in the amino acid sequence of SEQ ID NO: 154 or        ly, numbered according to the Kabat EU numbering system;        T366W and F405W mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, and introducing T394S and Y407A mutations in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   q) introducing F405W and Y407A mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing T366W and        T394S mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system; or    -   r) introducing a T366W mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing T366S, L368A, and Y407V        mutations in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system.

374. The masked cytokine of any one of embodiments 352-365, wherein themodifications promoting the association of the first and the secondhalf-life extension domain comprise:

-   -   a) introducing a K409E mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   b) introducing a K409E mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   c) introducing a K409D mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   d) introducing a K409D mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   e) introducing a K392E mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   f) introducing a K392E mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   g) introducing a K392D mutation in the first antibody or        fragment thereof, and introducing a D399R mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   h) introducing a K392D mutation in the first antibody or        fragment thereof, and introducing a D399K mutation in the second        antibody or fragment thereof, numbered according to the Kabat EU        :em;        409D and K360D mutations in the first antibody or fragment        thereof, and introducing D399K and E356K mutations in the second        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   j) introducing K409D and K370D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   k) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K, E356K, and E357K        mutations in the second antibody or fragment thereof, numbered        according to the Kabat EU numbering system;    -   l) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing a D399K mutation in the        second antibody or fragment thereof, numbered according to the        Kabat EU numbering system;    -   m) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K and E356K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   n) introducing K409D and K392D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   o) introducing K409D and K370D mutations in the first antibody        or fragment thereof, and introducing D399K and E357K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   p) introducing a D399K mutation in the first antibody or        fragment thereof, and introducing K409D and K360D mutations in        the second antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   q) introducing K409D and K439D mutations in the first antibody        or fragment thereof, and introducing D399K and E356K mutations        in the second antibody or fragment thereof, numbered according        to the Kabat EU numbering system;    -   r) introducing a K409E mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   s) introducing a K409E mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   t) introducing a K409D mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        :em;        K409D mutation in the second antibody or fragment thereof, and        introducing a D399R mutation in the first antibody or fragment        thereof, numbered according to the Kabat EU numbering system;    -   v) introducing a K392E mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   w) introducing a K392E mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   x) introducing a K392D mutation in the second antibody or        fragment thereof, and introducing a D399R mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   y) introducing a K392D mutation in the second antibody or        fragment thereof, and introducing a D399K mutation in the first        antibody or fragment thereof, numbered according to the Kabat EU        numbering system;    -   z) introducing K409D and K360D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;    -   aa) introducing K409D and K370D mutations in the second antibody        or fragment thereof, and introducing D399K and E357K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system;

ab) introducing K409D and K392D mutations in the second antibody orfragment thereof, and introducing D399K, E356K, and E357K mutations inthe first antibody or fragment thereof, numbered according to the KabatEU numbering system;

ac) introducing K409D and K392D mutations in the second antibody orfragment thereof, and introducing a D399K mutation in the first antibodyor fragment thereof, numbered according to the Kabat EU numberingsystem;

ad) introducing K409D and K392D mutations in the second antibody orfragment thereof, and introducing D399K and E356K mutations in the firstantibody or fragment thereof, numbered according to the Kabat EUnumbering system;

ae) introducing K409D and K392D mutations in the second antibody orfragment thereof, and introducing D399K and E357K mutations in the firstantibody or fragment thereof, numbered according to the Kabat EUnumbering system;

af) introducing K409D and K370D mutations in the second antibody orfragment thereof, and introducing D399K and E357K mutations in the firstantibody or fragment thereof, numbered according

J numbering system;

a D399K mutation in the second antibody or fragment thereof, andintroducing K409D and K360D mutations in the first antibody or fragmentthereof, numbered according to the Kabat EU numbering system; or

-   -   ah) introducing K409D and K439D mutations in the second antibody        or fragment thereof, and introducing D399K and E356K mutations        in the first antibody or fragment thereof, numbered according to        the Kabat EU numbering system.

375. The masked cytokine of any one of embodiments 352-365, wherein theamino acid sequence of the first antibody or fragment thereof and theamino acid sequence of the second antibody or fragment thereof areproduced by:

-   -   a) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   b) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   c) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   d) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   e) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   f) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   g) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   h) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;        409D and K360D mutations in the amino acid sequence of SEQ ID        NO: 154 or 169, and introducing D399K and E356K mutations in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   j) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   k) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K, E356K,        and E357K mutations in the amino acid sequence of SEQ ID NO: 154        or 169, respectively, numbered according to the Kabat EU        numbering system;    -   l) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing a D399K        mutation in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   m) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   n) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   o) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   p) introducing a D399K mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing K409D and K360D mutations        in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   q) introducing K409D and K439D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   r) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   s) introducing a K409E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   t) introducing a K409D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        ,rding to the Kabat EU numbering system;        K409D mutation in the amino acid sequence of SEQ ID NO: 154 or        169, and introducing a D399R mutation in the amino acid sequence        of SEQ ID NO: 154 or 169, respectively, numbered according to        the Kabat EU numbering system;    -   v) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   w) introducing a K392E mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   x) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399R mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   y) introducing a K392D mutation in the amino acid sequence of        SEQ ID NO: 154 or 169, and introducing a D399K mutation in the        amino acid sequence of SEQ ID NO: 154 or 169, respectively,        numbered according to the Kabat EU numbering system;    -   z) introducing K409D and K360D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   aa) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   ab) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K, E356K,        and E357K mutations in the amino acid sequence of SEQ ID NO: 154        or 169, respectively, numbered according to the Kabat EU        numbering system;    -   ac) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing a D399K        mutation in the amino acid sequence of SEQ ID NO: 154 or 169,        respectively, numbered according to the Kabat EU numbering        system;    -   ad) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, numbered according to the Kabat EU numbering system;    -   ae) introducing K409D and K392D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system;    -   af) introducing K409D and K370D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E357K mutations in the amino acid sequence of SEQ ID NO: 154 or        ly, numbered according to the Kabat EU numbering system;        a D399K mutation in the amino acid sequence of SEQ ID NO: 154 or        169, and introducing K409D and K360D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, respectively, numbered        according to the Kabat EU numbering system; or    -   ah) introducing K409D and K439D mutations in the amino acid        sequence of SEQ ID NO: 154 or 169, and introducing D399K and        E356K mutations in the amino acid sequence of SEQ ID NO: 154 or        169, respectively, numbered according to the Kabat EU numbering        system.

376. The masked cytokine of any one of embodiments 333-375, wherein thefirst linker comprises a first cleavable peptide; and/or wherein thesecond linker comprises a second cleavable peptide.

377. The masked cytokine of any one of embodiments 333-376, wherein thefirst linker comprises a first N-terminal spacer domain, and/or a firstC-terminal spacer domain.

378. The masked cytokine of embodiment 377, wherein the first linkercomprises:

-   -   a) the first N-terminal spacer domain, the first cleavable        peptide, and the first C-terminal spacer domain;    -   b) the first N-terminal spacer domain and the first cleavable        peptide;    -   c) the first N-terminal spacer domain and the first C-terminal        spacer domain;    -   d) the first cleavable peptide and the first C-terminal spacer        domain;    -   e) the first N-terminal spacer domain; or    -   f) the first C-terminal spacer domain.

379. The masked cytokine of any one of embodiments 333-378, wherein thesecond linker comprises a second N-terminal spacer domain, and/or asecond C-terminal spacer domain.

380. The masked cytokine of embodiment 379, wherein the second linkercomprises:

-   -   a) the second N-terminal spacer domain, the second cleavable        peptide, and the second C-terminal spacer domain;    -   b) the second N-terminal spacer domain and the second cleavable        peptide;    -   c) the second N-terminal spacer domain and the second C-terminal        spacer domain;    -   d) the second cleavable peptide and the second C-terminal spacer        domain;    -   e) the second N-terminal spacer domain; or    -   f) the second C-terminal spacer domain        tsked cytokine of any one of embodiments 376-380, wherein the        first cleavable peptide comprises an amino acid sequence        selected from the group consisting of SEQ ID NOs: 96-153,        236-242, 264, 270-302, 306-317, 342-347, 356-415, 420-491,        494-501, 504-535, and 538-555; and/or wherein the second        cleavable peptide comprises an amino acid sequence selected from        the group consisting of SEQ ID NOs: 96-153, 236-242, 264,        270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535,        and 538-555.

382. The masked cytokine of any one of embodiments 377-381, wherein thefirst N-terminal spacer domain comprises an amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799, and/or the first C-terminal spacerdomain comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340,341, 727, 794, and 799.

383. The masked cytokine of any one of embodiments 376-380, wherein thefirst cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

384. The masked cytokine of embodiment 383, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

385. The masked cytokine of any one of embodiments 379-384, wherein thesecond N-terminal spacer domain comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 20-95, 235, 268, 269,303-305, 323-338, 340, 341, 727, 794, and 799, and/or the secondC-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799.

386. The masked cytokine of any one of embodiments 376-385, wherein thesecond cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

tsked cytokine of embodiment 386, wherein the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555comprises an N-terminus and a C-terminus, and the amino acid sequenceselected from the group consisting of SEQ ID NOs: 236-242 is linked tothe N-terminus or the C-terminus of the amino acid sequence selectedfrom the group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

388. The masked cytokine of any one of embodiments 333-387, wherein thefirst linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812,and/or the second linker comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320,323-338, 340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and797-812.

389. The masked cytokine of any one of embodiments 334-388, wherein thethird linker comprises a third cleavable peptide.

390. The masked cytokine of any one of embodiments 334-389, wherein thethird linker comprises a third N-terminal spacer domain, and/or a thirdC-terminal spacer domain.

391. The masked cytokine of embodiment 390, wherein the third linkercomprises:

-   -   a) the third N-terminal spacer domain, the third cleavable        peptide, and the third C-terminal spacer domain;    -   b) the third N-terminal spacer domain and the third cleavable        peptide;    -   c) the third N-terminal spacer domain and the third C-terminal        spacer domain;    -   d) the third cleavable peptide and the third C-terminal spacer        domain;    -   e) the third N-terminal spacer domain; or    -   f) the third C-terminal spacer domain.

392. The masked cytokine of any one of embodiments 389-391, wherein thethird cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555;and/or wherein the third cleavable peptide comprises an amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153,236-242, 264, 270-302, 306-317, 342-347, 356-415, 420-491, 494-501,504-535, and 538-555.

tsked cytokine of any one of embodiments 390-392, wherein the thirdN-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799, and/or the third C-terminal spacerdomain comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340,341, 727, 794, and 799.

394. The masked cytokine of any one of embodiments 389-393, wherein thethird cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and an aminoacid sequence selected from the group consisting of SEQ ID NOs: 236-242.

395. The masked cytokine of embodiment 394, wherein the amino acidsequence selected from the group consisting of SEQ ID NOs: 96-153, 264,270-302, 306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and538-555 comprises an N-terminus and a C-terminus, and the amino acidsequence selected from the group consisting of SEQ ID NOs: 236-242 islinked to the N-terminus or the C-terminus of the amino acid sequenceselected from the group consisting of SEQ ID NOs: 96-153, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555.

396. The masked cytokine of any one of embodiments 334-395, wherein thethird linker comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320, 323-338,340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and 797-812,and/or the third linker comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320,323-338, 340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and797-812.

397. The masked cytokine of any one of embodiments 368-396, wherein thefourth linker comprises a fourth N-terminal spacer domain, and/or afourth C-terminal spacer domain.

398. The masked cytokine of embodiment 397, wherein the fourthN-terminal spacer domain comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305,323-338, 340, 341, 727, 794, and 799, and/or the fourth C-terminalspacer domain comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 20-95, 235, 268, 269, 303-305, 323-338, 340,341, 727, 794, and 799.

-   -   tsked cytokine of any one of embodiments 376-398, wherein the        first cleavable peptide, the second cleavable peptide, and/or        the third cleavable peptide is a substrate for a protease that        is co-localized in a region or a tissue expressing a cytokine        receptor.

400. The masked cytokine of embodiment 399, wherein the cytokinereceptor is an IL-2 cytokine receptor or an IL-15 cytokine receptor.

401. The masked cytokine of any one of embodiments 376-400, wherein thefirst cleavable peptide, the second cleavable peptide, and/or the thirdcleavable peptide is cleaved by one or more enzyme selected from thegroup consisting of: ABHD12, ADAM12, ABHD12B, ABHD13, ABHD17A, ADAM19,ADAM20, ADAM21, ADAM28, ADAM30, ADAM33, ADAMS, ABHD17A, ADAMDEC1,ADAMTS1, ADAMTS10, ADAMTS12, ADAMTS13, ADAMTS14, ADAMTS15, ADAMTS16,ADAMTS17, ADAMTS18, ADAMTS19, ADAMTS2, ADAMTS20, ADAMTS3, ADAMTS4,ABHD17B, ADAMTS5, ADAMTS6, ADAMTS7, ADAMTS8, ADAMTS9, ADAMTSL1,ADAMTSL2, ADAMTSL3, ABHD17C, ADAMTSL5, ASTL, BMP1, CELA1, CELA2A,CELA2B, CELA3A, CELA3B, ADAM10, ADAM15, ADAM17, ADAMS, ADAMTS4, CTSE,CTSF, ADAMTSL4, CMA1, CTRB1, CTRC, CTSO, CTRL, CTSA, CTSW, CTSB, CTSC,CTSD, ESP1, CTSG, CTSH, GZMA, GZMB, GZMH, CTSK, GZMM, CTSL, CTSS, CTSV,CTSZ, HTRA4, KLK10, KLK11, KLK13, KLK14, KLK2, KLK4, DPP4, KLK6, KLK7,KLKB1, ECE1, ECE2, ECEL1, MASP2, MEP1A, MEP1B, ELANE, FAP, GZMA, MMP11,GZMK, HGFAC, HPN, HTRA1, MMP11, MMP16, MMP17, MMP19, HTRA2, MMP20,MMP21, HTRA3, HTRA4, KEL, MMP23B, MMP24, MMP25, MMP26, MMP27, MMP28,KLK5, MMP3, MMP1, MMP8, MMP9, LGMN, LNPEP, MASP1, PAPPA, PAPPA2, PCSK1,NAPSA, PCSK5, PCSK6, MME, MMP1, MMP10, PLAT, PLAU, PLG, PRSS1, PRSS12,PRSS2, PRSS21, PRSS3, PRSS33, PRSS4, PRSS55, PRSS57, MMP12, PRSS8,PRSS9, PRTN3, MMP13, MMP14, ST14, TMPRSS10, TMPRSS11A, TMPRSS11D,TMPRSS11E, TMPRSS11F, TMPRSS12, TMPRSS13, MMP15, TMPRSS15, MMP2,TMPRSS2, TMPRSS3, TMPRSS4, TMPRSS5, TMPRSS6, TMPRSS7, TMPRSS9, NRDC,OVCH1, PAMR1, PCSK3, PHEX, TINAG, TPSAB1, TPSD1, and TPSG1.

402. The masked cytokine of any one of embodiments 332-401, wherein thefirst half-life extension domain and/or the second half-life extensiondomain is conjugated to an agent.

403. The masked cytokine of embodiment 402, wherein the agent is aninhibitor of tubulin polymerization, a DNA damaging agent, or a DNAsynthesis inhibitor.

-   -   tsked cytokine of embodiment 403, wherein the agent is a        maytansinoid, an auristatin, a pyrrolobenzodiazepine (PBD)        dimer, a calicheamicin, a duocarmycin, a indo-linobenzodiazepine        dimer or exatecan derivative Dxd.

405. The masked cytokine of embodiment 402, wherein the agent is animmune stimulant.

406. The masked cytokine of embodiment 405, wherein the immune stimulantis a stimulator of interferon genes (STING) agonist or a toll-likereceptor (TLR) agonist.

407. The masked cytokine of embodiment 406, wherein the STING agonist isa cyclic dinucleotide (CDN).

408. The masked cytokine of embodiment 407, wherein the CDN is selectedfrom the group consisting of cGAMP, c-di-AMP, c-di-GMP, cAIMP, c-di-IMP,4-(2-chloro-6-fluorobenzyl)-N-(furan-2-ylmethyl)-3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazine-6-carboxamide.

409. The masked cytokine of embodiment 406, wherein the TLR agonist isan agonist of a TLR selected from the group consisting of TLR1, TLR2,TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, and TLR10.

VIII. EXAMPLES

The invention will be more fully understood by reference to thefollowing examples. They should not, however, be construed as limitingthe scope of the invention. It is understood that the examples andembodiments described herein are for illustrative purposes only and thatvarious modifications or changes in light thereof will be suggested topersons skilled in the art and are to be included within the spirit andpurview of this application and scope of the appended claims.

Although some examples describe the engineering, production, and/ortesting of “masked” versions of an IL-2 polypeptide construct or IL-15polypeptide construct, some examples also employ parental “non-masked”versions of the IL-2 polypeptide construct or IL-15 polypeptideconstruct, such as for comparison, or other constructs that include oneor more of the components described herein that are tested as controlsfor comparison. Accordingly, the description of, for instance, testingdone on masked IL-2 polypeptide constructs does not necessarily meanthat non-masked versions of the construct were

-   -   !ering of Masked IL-2 Polypeptides and Masked IL-15 Polypeptides

Masked IL-2 polypeptide constructs and masked IL-15 polypeptideconstructs are generated in accordance with the teachings herein. In thesubsequent examples, some experiments involve use of the masked IL-2 andIL-15 polypeptide constructs in monomer form, and some experimentsinvolve use of the masked IL-2 and IL-15 polypeptide constructs in dimerform, such as a dimer formed through disulfide bonds linking two copiesof the same masked polypeptide construct (homodimer), or a heterodimerformed by two different polypeptides (see, e.g., Tables 8-11).

Masked IL-2 polypeptide constructs are generated that include an IL-2polypeptide or functional fragment thereof, a masking moiety, and ahalf-life extension domain, such as albumin, an antibody or fragmentthereof (e.g., an Fc region, heavy chain, and/or light chain), analbumin-binding peptide, an IgG-binding peptide, or a polyamino acidsequence. Some IL-2 polypeptide constructs are also generated thatinclude an IL-2 polypeptide or functional fragment thereof linked to ahalf-life extension domain without also including a masking moiety. Someof the constructs also include a linker that comprises a cleavablepeptide and links the masking moiety to the IL-2 polypeptide orfunctional fragment thereof, thereby resulting in an activatable maskedIL-2 polypeptide construct. Some of the constructs also include a linkerthat links the IL-2 polypeptide or functional fragment thereof to thehalf-life extension domain Some of the constructs also include a linkerthat links the IL-2 polypeptide or functional fragment thereof to themasking moiety. The masked IL-2 polypeptide constructs that do notinclude a cleavable peptide in the linker that links the IL-2polypeptide or functional fragment thereof to the masking moiety arealso referred to as non-activatable masked IL-2 polypeptide constructsor non-activatable IL-2 polypeptide constructs because they do notinclude a cleavable peptide. The structure and composition of exemplaryIL-2 polypeptide constructs are provided in Table 4.

TABLE 4 Cytokine or Structure functional Half-life (N- to C- Constructfragment Masking moiety extension terminal Amino Acid # thereof (C)Linker (L1) (MM) Linker (L2) domain (H) direction) Sequence 2001 SEQ IDNO: 1 — — — SEQ ID NO: 154 H-C 2002 SEQ ID NO: 1 SEQ ID NO: 20 SEQ IDNO: 9 — SEQ ID NO: 154 H-L1-MM-C 2003 SEQ ID NO: 1 SEQ ID NO: 21 SEQ IDNO: 9 — SEQ ID NO: 154 C-L1-MM-H 2004 SEQ ID NO: 3 — — — SEQ ID NO: 154H-C 2005 SEQ ID NO: 4 — — — SEQ ID NO: 154 H-C 2006 SEQ ID NO: 5 — — —SEQ ID NO: 154 H-C 2014 SEQ ID NO: 1 — SEQ ID NO: 10 SEQ ID NO: 15 SEQID NO: 154 H-C-L2-MM 2017 SEQ ID NO: 3 — SEQ ID NO: 10 SEQ ID NO: 15 SEQID NO: 154 H-C-L2-MM 2018 SEQ ID NO: 4 — SEQ ID NO: 10 SEQ ID NO: 15 SEQID NO: 154 H-C-L2-MM 2019 SEQ ID NO: 5 — SEQ ID NO: 10 SEQ ID NO: 15 SEQID NO: 154 H-C-L2-MM 2024 SEQ ID NO: 6 — — — SEQ ID NO: 154 H-C 2025 SEQID NO: 7 — — — SEQ ID NO: 154 H-C 2026 SEQ ID NO: 8 — — — SEQ ID NO: 154H-C 2027 SEQ ID NO: 1 SEQ ID NO: 20 SEQ ID NO: 9 SEQ ID NO: 30 SEQ IDNO: 154 H-L1-MM-L2-C 2028 SEQ ID NO: 1 SEQ ID NO: 20 SEQ ID NO: 9 SEQ IDNO: 31 SEQ ID NO: 154 H-L1-MM-L2-C 2029 SEQ ID NO: 1 SEQ ID NO: 20 SEQID NO: 9 SEQ ID NO: 32 SEQ ID NO: 154 H-L1-MM-L2-C 2030 SEQ ID NO: 1 SEQID NO: 20 SEQ ID NO: 9 SEQ ID NO: 33 SEQ ID NO: 154 H-L1-MM-L2-C 2031SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO: 9 SEQ ID NO: 29 SEQ ID NO: 154H-L1-MM-L2-C 2032 SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO: 9 SEQ ID NO: 30SEQ ID NO: 154 H-L1-MM-L2-C 2033 SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO: 9SEQ ID NO: 31 SEQ ID NO: 154 H-L1-MM-L2-C 2034 SEQ ID NO: 2 SEQ ID NO:20 SEQ ID NO: 9 SEQ ID NO: 32 SEQ ID NO: 154 H-L1-MM-L2-C 2035 SEQ IDNO: 2 SEQ ID NO: 20 SEQ ID NO: 9 SEQ ID NO: 33 SEQ ID NO: 154H-L1-MM-L2-C 2036 SEQ ID NO: 1 SEQ ID NO: 26 SEQ ID NO: 9 — SEQ ID NO:154 C-L1-MM-H 2037 SEQ ID NO: 1 SEQ ID NO: 27 SEQ ID NO: 9 — SEQ ID NO:154 C-L1-MM-H 2038 SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO: 9 — SEQ ID NO:154 C-L1-MM-H 2039 SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO: 9 — SEQ ID NO:154 C-L1-MM-H 2040 SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO: 9 — SEQ ID NO:154 C-L1-MM-H 2041 SEQ ID NO: 1 — SEQ ID NO: 10 SEQ ID NO: 16 SEQ ID NO:154 H-C-L2-MM 2042 SEQ ID NO: 1 — SEQ ID NO: 10 SEQ ID NO: 17 SEQ ID NO:154 H-C-L2-MM 2043 SEQ ID NO: 1 — SEQ ID NO: 10 SEQ ID NO: 18 SEQ ID NO:154 H-C-L2-MM 2044 SEQ ID NO: 1 — SEQ ID NO: 10 SEQ ID NO: 19 SEQ ID NO:154 H-C-L2-MM 2045 SEQ ID NO: 3 — SEQ ID NO: 10 SEQ ID NO: 16 SEQ ID NO:154 H-C-L2-MM 2046 SEQ ID NO: 3 — SEQ ID NO: 10 SEQ ID NO: 17 SEQ ID NO:154 H-C-L2-MM 2047 SEQ ID NO: 3 — SEQ ID NO: 10 SEQ ID NO: 18 SEQ ID NO:154 H-C-L2-MM 2048 SEQ ID NO: 3 — SEQ ID NO: 10 SEQ ID NO: 19 SEQ ID NO:154 H-C-L2-MM 2049 SEQ ID NO: 4 — SEQ ID NO: 10 SEQ ID NO: 16 SEQ ID NO:154 H-C-L2-MM 2050 SEQ ID NO: 4 — SEQ ID NO: 10 SEQ ID NO: 17 SEQ ID NO:154 H-C-L2-MM 2051 SEQ ID NO: 4 — SEQ ID NO: 10 SEQ ID NO: 18 SEQ ID NO:154 H-C-L2-MM 2052 SEQ ID NO: 4 — SEQ ID NO: 10 SEQ ID NO: 19 SEQ ID NO:154 H-C-L2-MM 2053 SEQ ID NO: 5 — SEQ ID NO: 10 SEQ ID NO: 16 SEQ ID NO:154 H-C-L2-MM 2054 SEQ ID NO: 5 — SEQ ID NO: 10 SEQ ID NO: 17 SEQ ID NO:154 H-C-L2-MM 2055 SEQ ID NO: 5 — SEQ ID NO: 10 SEQ ID NO: 18 SEQ ID NO:154 H-C-L2-MM 2056 SEQ ID NO: 5 — SEQ ID NO: 10 SEQ ID NO: 19 SEQ ID NO:154 H-C-L2-MM 2057 SEQ ID NO: 6 — SEQ ID NO: 10 SEQ ID NO: 15 SEQ ID NO:154 H-C-L2-MM 2058 SEQ ID NO: 6 — SEQ ID NO: 10 SEQ ID NO: 16 SEQ ID NO:154 H-C-L2-MM 2059 SEQ ID NO: 6 — SEQ ID NO: 10 SEQ ID NO: 17 SEQ ID NO:154 H-C-L2-MM 2060 SEQ ID NO: 6 — SEQ ID NO: 10 SEQ ID NO: 18 SEQ ID NO:154 H-C-L2-MM 2061 SEQ ID NO: 6 — SEQ ID NO: 10 SEQ ID NO: 19 SEQ ID NO:154 H-C-L2-MM 2062 SEQ ID NO: 7 — SEQ ID NO: 10 SEQ ID NO: 15 SEQ ID NO:154 H-C-L2-MM 2063 SEQ ID NO: 7 — SEQ ID NO: 10 SEQ ID NO: 16 SEQ ID NO:154 H-C-L2-MM 2064 SEQ ID NO: 7 — SEQ ID NO: 10 SEQ ID NO: 17 SEQ ID NO:154 H-C-L2-MM 2065 SEQ ID NO: 7 — SEQ ID NO: 10 SEQ ID NO: 18 SEQ ID NO:154 H-C-L2-MM 2066 SEQ ID NO: 7 — SEQ ID NO: 10 SEQ ID NO: 19 SEQ ID NO:154 H-C-L2-MM 2067 SEQ ID NO: 8 — SEQ ID NO: 10 SEQ ID NO: 15 SEQ ID NO:154 H-C-L2-MM 2068 SEQ ID NO: 8 — SEQ ID NO: 10 SEQ ID NO: 16 SEQ ID NO:154 H-C-L2-MM 2069 SEQ ID NO: 8 — SEQ ID NO: 10 SEQ ID NO: 17 SEQ ID NO:154 H-C-L2-MM 2070 SEQ ID NO: 8 — SEQ ID NO: 10 SEQ ID NO: 18 SEQ ID NO:154 H-C-L2-MM 2071 SEQ ID NO: 8 — SEQ ID NO: 10 SEQ ID NO: 19 SEQ ID NO:154 H-C-L2-MM 2109 SEQ ID NO: 2 — — — SEQ ID NO: 154 H-C AK032 SEQ IDNO: 1 — — — SEQ ID NO: 154 H-C SEQ ID NO: 556 AK033 SEQ ID NO: 1 SEQ IDNO: 20 SEQ ID NO: 9 SEQ ID NO: 29 SEQ ID NO: 154 H-L1-MM-L2-C SEQ ID NO:557 AK034 SEQ ID NO: 1 SEQ ID NO: 21 SEQ ID NO: 9 — SEQ ID NO: 154C-L1-MM-H SEQ ID NO: 558 AK035 SEQ ID NO: 3 — — — SEQ ID NO: 154 H-C SEQID NO: 559 AK036 SEQ ID NO: 4 — — — SEQ ID NO: 154 H-C SEQ ID NO: 560AK037 SEQ ID NO: 5 — — — SEQ ID NO: 154 H-C SEQ ID NO: 561 AK040 SEQ IDNO: 1 SEQ ID NO: 15 SEQ ID NO: 10 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO:566 AK042 SEQ ID NO: 6 — — — SEQ ID NO: 154 H-C SEQ ID NO: 568 AK043 SEQID NO: 7 — — — SEQ ID NO: 154 H-C SEQ ID NO: 569 AK044 SEQ ID NO: 8 — —— SEQ ID NO: 154 H-C SEQ ID NO: 570 AK045 SEQ ID NO: 1 SEQ ID NO: 20 SEQID NO: 9 SEQ ID NO: 30 SEQ ID NO: 154 H-L1-MM-L2-C SEQ ID NO: 571 AK046SEQ ID NO: 1 SEQ ID NO: 20 SEQ ID NO: 9 SEQ ID NO: 31 SEQ ID NO: 154H-L1-MM-L2-C SEQ ID NO: 572 AK047 SEQ ID NO: 1 SEQ ID NO: 20 SEQ ID NO:9 SEQ ID NO: 32 SEQ ID NO: 154 H-L1-MM-L2-C SEQ ID NO: 573 AK048 SEQ IDNO: 1 SEQ ID NO: 20 SEQ ID NO: 9 SEQ ID NO: 33 SEQ ID NO: 154H-L1-MM-L2-C SEQ ID NO: 574 AK049 SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO:9 SEQ ID NO: 29 SEQ ID NO: 154 H-L1-MM-L2-C SEQ ID NO: 575 AK050 SEQ IDNO: 2 SEQ ID NO: 20 SEQ ID NO: 9 SEQ ID NO: 30 SEQ ID NO: 154H-L1-MM-L2-C SEQ ID NO: 576 AK051 SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO:9 SEQ ID NO: 31 SEQ ID NO: 154 H-L1-MM-L2-C SEQ ID NO: 577 AK052 SEQ IDNO: 2 SEQ ID NO: 20 SEQ ID NO: 9 SEQ ID NO: 32 SEQ ID NO: 154H-L1-MM-L2-C SEQ ID NO: 578 AK053 SEQ ID NO: 2 SEQ ID NO: 20 SEQ ID NO:9 SEQ ID NO: 33 SEQ ID NO: 154 H-L1-MM-L2-C SEQ ID NO: 579 AK054 SEQ IDNO: 1 SEQ ID NO: 26 SEQ ID NO: 9 — SEQ ID NO: 154 C-L1-MM-H SEQ ID NO:580 AK055 SEQ ID NO: 1 SEQ ID NO: 27 SEQ ID NO: 9 — SEQ ID NO: 154C-L1-MM-H SEQ ID NO: 581 AK056 SEQ ID NO: 2 SEQ ID NO: 21 SEQ ID NO: 9 —SEQ ID NO: 154 C-L1-MM-H SEQ ID NO: 582 AK057 SEQ ID NO: 2 SEQ ID NO: 26SEQ ID NO: 9 — SEQ ID NO: 154 C-L1-MM-H SEQ ID NO: 583 AK058 SEQ ID NO:2 SEQ ID NO: 27 SEQ ID NO: 9 — SEQ ID NO: 154 C-L1-MM-H SEQ ID NO: 584AK059 SEQ ID NO: 1 SEQ ID NO: 16 SEQ ID NO: 10 — SEQ ID NO: 154H-C-L1-MM SEQ ID NO: 585 AK060 SEQ ID NO: 1 SEQ ID NO: 17 SEQ ID NO: 10— SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 586 AK061 SEQ ID NO: 1 SEQ ID NO:18 SEQ ID NO: 10 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 587 AK062 SEQ IDNO: 1 SEQ ID NO: 19 SEQ ID NO: 10 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO:588 AK063 SEQ ID NO: 3 SEQ ID NO: 16 SEQ ID NO: 10 — SEQ ID NO: 154H-C-L1-MM SEQ ID NO: 589 AK064 SEQ ID NO: 3 SEQ ID NO: 17 SEQ ID NO: 10— SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 590 AK065 SEQ ID NO: 3 SEQ ID NO:18 SEQ ID NO: 10 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 591 AK066 SEQ IDNO: 3 SEQ ID NO: 19 SEQ ID NO: 10 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO:592 AK067 SEQ ID NO: 6 SEQ ID NO: 15 SEQ ID NO: 10 — SEQ ID NO: 154H-C-L1-MM SEQ ID NO: 593 AK068 SEQ ID NO: 6 SEQ ID NO: 16 SEQ ID NO: 10— SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 594 AK069 SEQ ID NO: 6 SEQ ID NO:17 SEQ ID NO: 10 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 595 AK070 SEQ IDNO: 6 SEQ ID NO: 18 SEQ ID NO: 10 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO:596 AK071 SEQ ID NO: 6 SEQ ID NO: 19 SEQ ID NO: 10 — SEQ ID NO: 154H-C-L1-MM SEQ ID NO: 597 AK112 SEQ ID NO: 1 SEQ ID NO: 15 SEQ ID NO: 261— SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 602 AK080 SEQ ID NO: 2 — — — SEQID NO: 154 H-C SEQ ID NO: 607 AK082 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQID NO: 155 H-L1-MM SEQ ID NO: 609 AK083 SEQ ID NO: 1 SEQ ID NO: 15 SEQID NO: 226 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 610 AK084 SEQ ID NO: 1SEQ ID NO: 16 SEQ ID NO: 226 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 611AK085 SEQ ID NO: 1 SEQ ID NO: 17 SEQ ID NO: 226 — SEQ ID NO: 154H-C-L1-MM SEQ ID NO: 612 AK086 SEQ ID NO: 1 SEQ ID NO: 18 SEQ ID NO: 226— SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 613 AK087 SEQ ID NO: 1 SEQ ID NO:19 SEQ ID NO: 226 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 614 AK096 SEQ IDNO: 1 SEQ ID NO: 762 — — SEQ ID NO: 154 H-C-Ll SEQ ID NO: 627 AK097 SEQID NO: 1 SEQ ID NO: 763 — — SEQ ID NO: 154 H-C-Ll SEQ ID NO: 628 AK098SEQ ID NO: 1 SEQ ID NO: 764 — — SEQ ID NO: 154 H-C-Ll SEQ ID NO: 629AK099 SEQ ID NO: 1 SEQ ID NO: 765 — — SEQ ID NO: 154 H-C-Ll SEQ ID NO:630 AK100 SEQ ID NO: 1 SEQ ID NO: 766 — — SEQ ID NO: 154 H-C-Ll SEQ IDNO: 631 AK101 SEQ ID NO: 1 SEQ ID NO: 767 — — SEQ ID NO: 154 H-C-Ll SEQID NO: 632 AK102 SEQ ID NO: 1 SEQ ID NO: 768 — — SEQ ID NO: 154 H-C-LlSEQ ID NO: 633 AK103 SEQ ID NO: 1 SEQ ID NO: 769 — — SEQ ID NO: 154H-C-Ll SEQ ID NO: 634 AK104 SEQ ID NO: 1 SEQ ID NO: 770 — — SEQ ID NO:154 H-C-Ll SEQ ID NO: 635 AK105 SEQ ID NO: 1 SEQ ID NO: 771 — — SEQ IDNO: 154 H-C-Ll SEQ ID NO: 636 AK106 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQID NO: 154 H-L1-MM SEQ ID NO: 637 AK112 SEQ ID NO: 1 SEQ ID NO: 15 SEQID NO: 261 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 602 AK113 SEQ ID NO: 3SEQ ID NO: 15 SEQ ID NO: 261 — SEQ ID NO: 154 H-C-L1-MM SEQ ID NO: 642AK114 SEQ ID NO: 6 SEQ ID NO: 15 SEQ ID NO: 261 — SEQ ID NO: 154H-C-L1-MM SEQ ID NO: 643 AK115 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 644 AK116 SEQ ID NO: 775 — — — SEQ ID NO: 154H-C SEQ ID NO: 645 AK117 SEQ ID NO: 776 — — — SEQ ID NO: 154 H-C SEQ IDNO: 646 AK118 SEQ ID NO: 777 — — — SEQ ID NO: 154 H-C SEQ ID NO: 647AK119 SEQ ID NO: 778 — — — SEQ ID NO: 154 H-C SEQ ID NO: 648 AK120 SEQID NO: 779 — — — SEQ ID NO: 154 H-C SEQ ID NO: 649 AK121 SEQ ID NO: 780— — — SEQ ID NO: 154 H-C SEQ ID NO: 650 AK122 SEQ ID NO: 781 — — — SEQID NO: 154 H-C SEQ ID NO: 651 AK123 SEQ ID NO: 782 — — — SEQ ID NO: 154H-C SEQ ID NO: 652 AK124 SEQ ID NO: 783 — — — SEQ ID NO: 154 H-C SEQ IDNO: 653 AK125 SEQ ID NO: 784 — — — SEQ ID NO: 154 H-C SEQ ID NO: 654AK126 SEQ ID NO: 785 — — — SEQ ID NO: 154 H-C SEQ ID NO: 655 AK127 SEQID NO: 786 — — — SEQ ID NO: 154 H-C SEQ ID NO: 656 AK128 SEQ ID NO: 787— — — SEQ ID NO: 154 H-C SEQ ID NO: 657 AK129 SEQ ID NO: 788 — — — SEQID NO: 154 H-C SEQ ID NO: 658 AK130 SEQ ID NO: 789 — — — SEQ ID NO: 154H-C SEQ ID NO: 659 AK131 SEQ ID NO: 790 — — — SEQ ID NO: 154 H-C SEQ IDNO: 660 AK132 SEQ ID NO: 791 — — — SEQ ID NO: 154 H-C SEQ ID NO: 661AK133 SEQ ID NO: 792 — — — SEQ ID NO: 154 H-C SEQ ID NO: 662

Masked IL-15 polypeptide constructs are generated that include an IL-15polypeptide or functional fragment thereof, a masking moiety, and ahalf-life extension domain, such as albumin, an antibody or fragmentthereof (e.g., an Fc region, heavy chain, and/or light chain), analbumin-binding peptide, an IgG-binding peptide, or a polyamino acidsequence. Some IL-15 polypeptide constructs are also generated thatinclude an IL-15 polypeptide or functional fragment thereof linked to ahalf-life extension domain without also including a masking moiety. Someof the constructs also include a linker that comprises a cleavablepeptide and links the masking moiety to the IL-15 polypeptide orfunctional fragment thereof, thereby resulting in an activatable maskedIL-15 polypeptide construct. Some of the constructs also include alinker that links the IL-15 polypeptide or functional fragment thereofto the half-life extension domain. Some of the constructs also include alinker that links the IL-15 polypeptide or functional fragment thereofto the masking moiety. The masked IL-15 polypeptide constructs that donot include a cleavable peptide in the linker that links the IL-15polypeptide or functional fragment thereof to the masking moiety arealso referred to as non-activatable masked IL-15 polypeptide constructsor non-activatable IL-15 polypeptide constructs because they do notinclude a cleavable peptide. Some IL-15 polypeptide constructs are alsogenerated that include a masking moiety comprising the amino acidsequence of SEQ ID NO: 261. The structure and composition of exemplaryIL-15 polypeptide constructs are provided in Table 5.

TABLE 5 Cytokine or Structure functional Half-life (N- to C- Constructfragment Masking moiety extension terminal # thereof (C) Linker (L1)(MM) Linker (L2) domain (H) direction) 3000 SEQ ID NO: 167 SEQ ID NO: 20SEQ ID NO: 10 SEQ ID NO: 15 SEQ ID NO: 154 H-L1-MM-L2-C 3001 SEQ ID NO:167 SEQ ID NO: 20 SEQ ID NO: 161 SEQ ID NO: 16 SEQ ID NO: 154H-L1-MM-L2-C 3002 SEQ ID NO: 167 SEQ ID NO: 20 SEQ ID NO: 162 SEQ ID NO:17 SEQ ID NO: 154 H-L1-MM-L2-C 3003 SEQ ID NO: 167 SEQ ID NO: 20 SEQ IDNO: 163 SEQ ID NO: 18 SEQ ID NO: 154 H-L1-MM-L2-C 3004 SEQ ID NO: 167SEQ ID NO: 20 SEQ ID NO: 164 SEQ ID NO: 19 SEQ ID NO: 154 H-L1-MM-L2-C3005 SEQ ID NO: 167 SEQ ID NO: 20 SEQ ID NO: 165 SEQ ID NO: 15 SEQ IDNO: 154 H-L1-MM-L2-C 3006 SEQ ID NO: 167 SEQ ID NO: 20 SEQ ID NO: 219SEQ ID NO: 16 SEQ ID NO: 154 H-L1-MM-L2-C 3007 SEQ ID NO: 167 SEQ ID NO:20 SEQ ID NO: 220 SEQ ID NO: 17 SEQ ID NO: 154 H-L1-MM-L2-C 3008 SEQ IDNO: 167 SEQ ID NO: 20 SEQ ID NO: 221 SEQ ID NO: 18 SEQ ID NO: 154H-L1-MM-L2-C 3009 SEQ ID NO: 167 SEQ ID NO: 20 SEQ ID NO: 222 SEQ ID NO:19 SEQ ID NO: 154 H-L1-MM-L2-C 3010 SEQ ID NO: 167 SEQ ID NO: 20 SEQ IDNO: 223 SEQ ID NO: 15 SEQ ID NO: 154 C-L2-MM-L1-H 3011 SEQ ID NO: 167SEQ ID NO: 20 SEQ ID NO: 224 SEQ ID NO: 16 SEQ ID NO: 154 C-L2-MM-L1-H3012 SEQ ID NO: 167 SEQ ID NO: 20 SEQ ID NO: 225 SEQ ID NO: 17 SEQ IDNO: 154 C-L2-MM-L1-H 3013 SEQ ID NO: 167 SEQ ID NO: 20 SEQ ID NO: 226SEQ ID NO: 18 SEQ ID NO: 154 C-L2-MM-L1-H 3014 SEQ ID NO: 167 SEQ ID NO:20 SEQ ID NO: 227 SEQ ID NO: 19 SEQ ID NO: 154 C-L2-MM-L1-H 3015 SEQ IDNO: 167 SEQ ID NO: 20 SEQ ID NO: 228 SEQ ID NO: 15 SEQ ID NO: 154C-L2-MM-L1-H 3016 SEQ ID NO: 167 SEQ ID NO: 20 SEQ ID NO: 229 SEQ ID NO:16 SEQ ID NO: 154 C-L2-MM-L1-H 3017 SEQ ID NO: 167 SEQ ID NO: 20 SEQ IDNO: 232 SEQ ID NO: 17 SEQ ID NO: 154 C-L2-MM-L1-H 3018 SEQ ID NO: 167SEQ ID NO: 20 SEQ ID NO: 233 SEQ ID NO: 18 SEQ ID NO: 154 C-L2-MM-L1-H3019 SEQ ID NO: 167 SEQ ID NO: 20 SEQ ID NO: 234 SEQ ID NO: 19 SEQ IDNO: 154 C-L2-MM-L1-H

Also generated are masked IL-2 polypeptide constructs that include anIL-2 polypeptide or functional fragment thereof, a first masking moiety,a second masking moiety, and a half-life extension domain, such asalbumin, an antibody or fragment thereof (e.g., an Fc region, heavychain, and/or light chain), an albumin-binding peptide, an IgG-bindingpeptide, or a polyamino acid sequence. Some of the constructs alsoinclude a linker that links the first masking moiety to the IL-2polypeptide or functional fragment thereof. Some of the constructs alsoinclude a linker that links the second masking moiety to the IL-2polypeptide or functional fragment thereof. Some of the constructsinclude a cleavable peptide in the linker linking the first maskingmoiety to the IL-2 polypeptide or functional fragment thereof and/or thelinker linking the second masking moiety to the IL-2 polypeptide orfunctional fragment thereof, thereby resulting in an activatable maskedIL-2 polypeptide construct. Some of the constructs also include a linkerlinking the second masking moiety to the half-life extension domain. Themasked IL-2 polypeptide constructs that do not include a cleavablepeptide in either of the linkers that link the IL-2 polypeptide orfunctional fragment thereof to the first masking moiety or the secondmasking moiety are also referred to as non-activatable masked IL-2polypeptide constructs or non-activatable IL-2 polypeptide constructsbecause they do not include a cleavable peptide. The structure andcomposition of exemplary IL-2 polypeptide constructs are provided inTable 6.

TABLE 6 Cytokine or Structure Masking functional Masking Half-life (N-to C- Construct moiety Linker fragment Linker moiety Linker extensionterminal Amino Acid # (MM1) (L1) thereof (C) (L2) (MM2) (L3) domain (H)direction) Sequence 2015 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQID H-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 15 NO: 1542072 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 16 NO: 1542073 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 17 NO: 1542074 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 18 NO: 1542075 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 19 NO: 1542076 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 2 NO: 29 NO: 10 NO: 16 NO: 1542077 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 2 NO: 29 NO: 10 NO: 17 NO: 1542078 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 2 NO: 29 NO: 10 NO: 18 NO: 1542079 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 9 NO: 20 NO: 2 NO: 29 NO: 10 NO: 19 NO: 154AK041 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 SEQ ID NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 15 NO:154 NO: 567 AK072 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 SEQ ID NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 16 NO:154 NO: 598 AK073 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 SEQ ID NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 17 NO:154 NO: 599 AK074 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 SEQ ID NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 18 NO:154 NO: 600 AK075 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 SEQ ID NO: 9 NO: 20 NO: 1 NO: 29 NO: 10 NO: 19 NO:154 NO: 601

Also generated are masked IL-15 polypeptide constructs that include anIL-15 polypeptide or functional fragment thereof, a first maskingmoiety, a second masking moiety, and a half-life extension domain, suchas albumin, an antibody or fragment thereof (e.g., an Fc region, heavychain, and/or light chain), an albumin-binding peptide, an IgG-bindingpeptide, or a polyamino acid sequence. Some of the constructs alsoinclude a linker that links the first masking moiety to the IL-15polypeptide or functional fragment thereof. Some of the constructs alsoinclude a linker that links the second masking moiety to the IL-15polypeptide or functional fragment thereof. Some of the constructsinclude a cleavable peptide in the linker linking the first maskingmoiety to the IL-15 polypeptide or functional fragment thereof and/orthe linker linking the second masking moiety to the IL-15 polypeptide orfunctional fragment thereof, thereby resulting in an activatable maskedIL-15 polypeptide construct. Some of the constructs also include alinker linking the second masking moiety to the half-life extensiondomain. Some of the constructs also include a second half-life extensiondomain that associates with the first half-life extension domain. Themasked IL-15 polypeptide constructs that do not include a cleavablepeptide in either of the linkers that link the IL-15 polypeptide orfunctional fragment thereof to the first masking moiety or the secondmasking moiety are also referred to as non-activatable masked IL-15polypeptide constructs or non-activatable IL-2 polypeptide constructsbecause they do not include a cleavable peptide. The structure andcomposition of exemplary IL-15 polypeptide constructs are provided inTable 7.

TABLE 7 Cytokine or Structure Masking functional Masking Half-life (N-to C- Construct moiety Linker fragment Linker moiety Linker extensionterminal Amino Acid # (MM1) (L1) thereof (C) (L2) (MM2) (L3) domain (H)direction) Sequence 3020 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQID H-L1-MM1-L2-C-L3-MM2 NO: 232 NO: 20 NO: 167 NO: 29 NO: 10 NO: 1q5 NO:154 3021 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 232 NO: 20 NO: 167 NO: 29 NO: 161 NO: 16 NO:154 3022 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 232 NO: 20 NO: 167 NO: 29 NO: 162 NO: 17 NO:154 3023 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 232 NO: 20 NO: 167 NO: 29 NO: 163 NO: 18 NO:154 3024 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 233 NO: 20 NO: 167 NO: 29 NO: 164 NO: 19 NO:154 3025 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 233 NO: 20 NO: 167 NO: 29 NO: 165 NO: 15 NO:154 3026 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 233 NO: 20 NO: 167 NO: 29 NO: 219 NO: 16 NO:154 3027 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 233 NO: 20 NO: 167 NO: 29 NO: 220 NO: 17 NO:154 3028 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 234 NO: 20 NO: 167 NO: 29 NO: 221 NO: 18 NO:154 3029 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-C-L3-MM2 NO: 234 NO: 20 NO: 167 NO: 29 NO: 222 NO: 19 NO:154 3030 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDMM2-L3-C-L2-MM1-L1-H NO: 234 NO: 20 NO: 167 NO: 29 NO: 227 NO: 15 NO:154 3031 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDMM2-L3-C-L2-MM1-L1-H NO: 234 NO: 20 NO: 167 NO: 29 NO: 228 NO: 16 NO:154 3032 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDMM2-L3-C-L2-MM1-L1-H NO: 234 NO: 20 NO: 167 NO: 29 NO: 229 NO: 17 NO:154 AK401 SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ IDH-L1-MM1-L2-MM2-L3-C SEQ ID NO: 261 NO: 28 NO: 167 NO: 318 NO: 825 NO:27 NO: 155 NO: 755 — — — — — — SEQ ID H SEQ ID NO: 616 NO: 616 AK403 SEQID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID SEQ ID H-L1-MM1-L2-MM2-L3-C SEQ IDNO: 261 NO: 28 NO: 167 NO: 318 NO: 825 NO: 27 NO: 155 NO: 756 — — — — —— SEQ ID H SEQ ID NO: 616 NO: 616 AK402 SEQ ID SEQ ID SEQ ID SEQ ID SEQID SEQ ID SEQ ID H-L1-MM1-L2-MM2-L3-C SEQ ID NO: 261 NO: 28 NO: 167 NO:319 NO: 825 NO: 27 NO: 155 NO: 757 — — — — — — SEQ ID H SEQ ID NO: 616NO: 616

Also generated are masked IL-2 polypeptide constructs that include anIL-2 polypeptide or functional fragment thereof, a masking moiety, afirst half-life extension domain, and a second half-life extensiondomain, such as albumin, an antibody or fragment thereof (e.g., an Fcregion, heavy chain, and/or light chain), an albumin-binding peptide, anIgG-binding peptide, or a polyamino acid sequence. The masking moiety islinked to the first half-life extension domain, the IL-2 polypeptide orfunctional fragment thereof is linked to the second half-life extensiondomain, and the first half-life extension domain and the secondhalf-life extension domain contain modifications promoting theassociation of the first and the second half-life extension domain. Inone exemplary embodiment, the masking moiety is linked to the firsthalf-life extension domain and includes the amino acid sequence of SEQID NO: 267, and the IL-2 polypeptide or functional fragment thereof islinked to the second half-life extension domain and includes the aminoacid sequence of SEQ ID NO: 266, and the first half-life extensiondomain and the second half-life extension domain contain modificationspromoting the association of the first and the second half-lifeextension domain. In one exemplary embodiment of a non-masked IL-2polypeptide construct, the embodiment comprises an IL-2 polypeptide orfunctional fragment thereof linked to a first half-life extensiondomain, and comprises a second half-life extension domain, where theIL-2 polypeptide or functional fragment thereof is linked to the firsthalf-life extension domain and includes the amino acid sequence of SEQID NO: 266, and the second half-life extension domain includes the aminoacid sequence of SEQ ID NO: 265. Some of the constructs also include alinker that links the masking moiety to the first half-life extensiondomain, and/or a linker that links the IL-2 polypeptide or functionalfragment thereof to the second half-life extension domain. The first andsecond half-life extension domain of some of the constructs are alsolinked. In some constructs, the first and second half-life extensiondomain of some of the constructs are linked by a linker. Some of theconstructs include a cleavable peptide in the linker linking the maskingmoiety to the first half-life extension domain and/or the linker linkingthe IL-2 polypeptide or functional fragment thereof to the secondhalf-life extension domain, thereby resulting in an activatable maskedIL-2 polypeptide construct. The masked IL-2 polypeptide constructs thatdo not include a cleavable peptide in either the linker that links theIL-2 polypeptide or functional fragment thereof to the second half-lifeextension domain or the linker that links the masking moiety to thefirst half-life extension domain are also referred to as non-activatablemasked IL-2 polypeptide constructs or non-activatable IL-2 polypeptideconstructs because they do not include a cleavable peptide. Thestructure and composition of exemplary IL-2 polypeptide constructs areprovided in Table 8.

TABLE 8 Cytokine or Structure functional Half-life (N- to C- Constructfragment Masking moiety extension terminal Amino Acid # thereof (C)Linker (L1) (MM) Linker (L2) domain (H) direction) Sequence 2007/2008SEQ ID NO: 1 SEQ ID NO: 22 — — SEQ ID NO: 157 C-L1-H — SEQ ID NO: 23 SEQID NO: 9 — SEQ ID NO: 158 MM-L1-H 2009/2010 — SEQ ID NO: 24 SEQ ID NO: 9— SEQ ID NO: 158 MM-L1-H SEQ ID NO: 1 SEQ ID NO: 25 — — SEQ ID NO: 157C-L1-H 2080/2081 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MMSEQ ID NO: 1 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C 2080/2082 — SEQ IDNO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 1 SEQ ID NO: 12— — SEQ ID NO: 156 H-L1-C 2080/2083 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQID NO: 155 H-L1-MM SEQ ID NO: 1 SEQ ID NO: 13 — — SEQ ID NO: 156 H-L1-C2080/2084 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 1 SEQ ID NO: 14 — — SEQ ID NO: 156 H-L1-C 2080/2085 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 3 SEQ ID NO: 11 — —SEQ ID NO: 156 H-L1-C 2080/2086 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 3 SEQ ID NO: 12 — — SEQ ID NO: 156 H-L1-C2080/2087 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 3 SEQ ID NO: 13 — — SEQ ID NO: 156 H-L1-C 2080/2088 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 3 SEQ ID NO: 14 — —SEQ ID NO: 156 H-L1-C 2080/2089 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 4 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C2080/2090 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 4 SEQ ID NO: 12 — — SEQ ID NO: 156 H-L1-C 2080/2091 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 4 SEQ ID NO: 13 — —SEQ ID NO: 156 H-L1-C 2080/2092 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 4 SEQ ID NO: 14 — — SEQ ID NO: 156 H-L1-C2080/2093 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 5 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C 2080/2094 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 5 SEQ ID NO: 12 — —SEQ ID NO: 156 H-L1-C 2080/2095 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 5 SEQ ID NO: 13 — — SEQ ID NO: 156 H-L1-C2080/2096 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 5 SEQ ID NO: 14 — — SEQ ID NO: 156 H-L1-C 2080/2097 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 6 SEQ ID NO: 11 — —SEQ ID NO: 156 H-L1-C 2080/2098 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 6 SEQ ID NO: 12 — — SEQ ID NO: 156 H-L1-C2080/2099 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 6 SEQ ID NO: 13 — — SEQ ID NO: 156 H-L1-C 2080/2100 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 6 SEQ ID NO: 14 — —SEQ ID NO: 156 H-L1-C 2080/2101 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 7 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C2080/2102 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 7 SEQ ID NO: 12 — — SEQ ID NO: 156 H-L1-C 2080/2103 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 7 SEQ ID NO: 13 — —SEQ ID NO: 156 H-L1-C 2080/2104 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 7 SEQ ID NO: 14 — — SEQ ID NO: 156 H-L1-C2080/2105 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 8 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C 2080/2106 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 8 SEQ ID NO: 12 — —SEQ ID NO: 156 H-L1-C 2080/2107 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 8 SEQ ID NO: 13 — — SEQ ID NO: 156 H-L1-C2080/2108 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 8 SEQ ID NO: 14 — — SEQ ID NO: 156 H-L1-C 5001/5002 SEQ ID NO: 260SEQ ID NO: 262 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 266 — — — — SEQ IDNO: 265 H SEQ ID NO: 265 5001/5003 SEQ ID NO: 260 SEQ ID NO: 262 — — SEQID NO: 156 H-L1-C SEQ ID NO: 266 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK038 SEQ ID NO: 1 SEQ ID NO: 22 — — SEQID NO: 157 C-L1-H SEQ ID NO: 562 — SEQ ID NO: 23 SEQ ID NO: 9 — SEQ IDNO: 158 MM-L1-H SEQ ID NO: 563 AK039 — SEQ ID NO: 24 SEQ ID NO: 9 — SEQID NO: 158 MM-L1-H SEQ ID NO: 564 SEQ ID NO: 1 SEQ ID NO: 25 — — SEQ IDNO: 157 C-L1-H SEQ ID NO: 565 AK076 SEQ ID NO: 1 SEQ ID NO: 11 — — SEQID NO: 156 H-L1-C SEQ ID NO: 608 — SEQ ID NO: 795 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 603 AK077 SEQ ID NO: 1 SEQ ID NO: 12 — — SEQID NO: 156 H-L1-C SEQ ID NO: 604 — SEQ ID NO: 795 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 603 AK078 SEQ ID NO: 1 SEQ ID NO: 13 — — SEQID NO: 156 H-L1-C SEQ ID NO: 605 — SEQ ID NO: 795 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 603 AK079 SEQ ID NO: 1 SEQ ID NO: 14 — — SEQID NO: 156 H-L1-C SEQ ID NO: 606 — SEQ ID NO: 795 SEQ ID NO: 10 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 603 AK081 SEQ ID NO: 1 SEQ ID NO: 11 — — SEQID NO: 156 H-L1-C SEQ ID NO: 608 — — — — SEQ ID NO: 265 H SEQ ID NO: 265AK088 SEQ ID NO: 1 — — — SEQ ID NO: 155 H-C SEQ ID NO: 615 — — — — SEQID NO: 616 H SEQ ID NO: 616 AK089 SEQ ID NO: 1 — — — SEQ ID NO: 155 H-CSEQ ID NO: 615 — SEQ ID NO: 15 SEQ ID NO: 10 — SEQ ID NO: 156 H-L1-MMSEQ ID NO: 617 AK090 SEQ ID NO: 1 — — — SEQ ID NO: 721 H-C SEQ ID NO:618 — — — — SEQ ID NO: 619 H SEQ ID NO: 619 AK091 SEQ ID NO: 1 — — — SEQID NO: 721 H-C SEQ ID NO: 618 — SEQ ID NO: 15 SEQ ID NO: 10 — SEQ ID NO:772 H-L1-MM SEQ ID NO: 620 AK092 SEQ ID NO: 1 — — — SEQ ID NO: 793 H-CSEQ ID NO: 621 — — — — SEQ ID NO: 622 H SEQ ID NO: 622 AK093 SEQ ID NO:1 — — — SEQ ID NO: 793 H-C SEQ ID NO: 621 — SEQ ID NO: 15 SEQ ID NO: 10— SEQ ID NO: 773 H-L1-MM SEQ ID NO: 623 AK094 SEQ ID NO: 1 — — — SEQ IDNO: 796 H-C SEQ ID NO: 624 — — — — SEQ ID NO: 625 H SEQ ID NO: 625 AK095SEQ ID NO: 1 — — — SEQ ID NO: 796 H-C SEQ ID NO: 624 — SEQ ID NO: 15 SEQID NO: 10 — SEQ ID NO: 774 H-L1-MM SEQ ID NO: 626 AK107 — SEQ ID NO: 15SEQ ID NO: 261 — SEQ ID NO: 156 H-L1-MM SEQ ID NO: 638 SEQ ID NO: 1 — —— SEQ ID NO: 155 H-C SEQ ID NO: 615 AK108 — SEQ ID NO: 15 SEQ ID NO: 261— SEQ ID NO: 772 H-L1-MM SEQ ID NO: 639 SEQ ID NO: 1 — — — SEQ ID NO:721 H-C SEQ ID NO: 618 AK109 — SEQ ID NO: 15 SEQ ID NO: 261 — SEQ ID NO:773 H-L1-MM SEQ ID NO: 640 SEQ ID NO: 1 — — — SEQ ID NO: 793 H-C SEQ IDNO: 621 AK110 — SEQ ID NO: 15 SEQ ID NO: 261 — SEQ ID NO: 774 H-L1-MMSEQ ID NO: 641 SEQ ID NO: 1 — — — SEQ ID NO: 796 H-C SEQ ID NO: 624AK111 SEQ ID NO: 1 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO:608 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO:267 AK163 SEQ ID NO: 1 SEQ ID NO: 11 — — SEQ ID NO: 793 H-L1-C SEQ IDNO: 663 — — — — SEQ ID NO: 622 H SEQ ID NO: 622 AK164 SEQ ID NO: 1 SEQID NO: 11 — — SEQ ID NO: 793 H-L1-C SEQ ID NO: 663 — SEQ ID NO: 795 SEQID NO: 261 — SEQ ID NO: 773 H-L1-MM SEQ ID NO: 664 AK165 SEQ ID NO: 1SEQ ID NO: 11 — — SEQ ID NO: 796 H-L1-C SEQ ID NO: 665 — — — — SEQ IDNO: 625 H SEQ ID NO: 625 AK166 SEQ ID NO: 1 SEQ ID NO: 11 — — SEQ ID NO:796 H-L1-C SEQ ID NO: 665 — SEQ ID NO: 795 SEQ ID NO: 261 — SEQ ID NO:774 H-L1-MM SEQ ID NO: 666 AK167 SEQ ID NO: 3 SEQ ID NO: 11 — — SEQ IDNO: 156 H-L1-C SEQ ID NO: 667 — — — — SEQ ID NO: 265 H SEQ ID NO: 265AK168 SEQ ID NO: 3 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO:667 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO:267 AK169 SEQ ID NO: 6 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ IDNO: 669 — — — — SEQ ID NO: 265 H SEQ ID NO: 265 AK170 — SEQ ID NO: 28SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 SEQ ID NO: 6 SEQID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 669 AK171 SEQ ID NO: 1SEQ ID NO: 11 — — SEQ ID NO: 155 H-L1-C SEQ ID NO: 670 — — — — SEQ IDNO: 616 H SEQ ID NO: 616 AK172 SEQ ID NO: 1 SEQ ID NO: 11 — — SEQ ID NO:155 H-L1-C SEQ ID NO: 670 — SEQ ID NO: 795 SEQ ID NO: 261 — SEQ ID NO:156 H-L1-MM SEQ ID NO: 671 AK184 SEQ ID NO: 1 SEQ ID NO: 800 — — SEQ IDNO: 156 H-L1-C SEQ ID NO: 672 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK185 SEQ ID NO: 1 SEQ ID NO: 185 — — SEQID NO: 156 H-L1-C SEQ ID NO: 673 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK186 SEQ ID NO: 1 SEQ ID NO: 802 — — SEQID NO: 156 H-L1-C SEQ ID NO: 674 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK187 SEQ ID NO: 1 SEQ ID NO: 803 — — SEQID NO: 156 H-L1-C SEQ ID NO: 675 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK188 SEQ ID NO: 3 SEQ ID NO: 804 — — SEQID NO: 156 H-L1-C SEQ ID NO: 676 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK189 SEQ ID NO: 1 SEQ ID NO: 805 — — SEQID NO: 156 H-L1-C SEQ ID NO: 677 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK190 SEQ ID NO: 1 SEQ ID NO: 806 — — SEQID NO: 156 H-L1-C SEQ ID NO: 678 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK191 SEQ ID NO: 3 SEQ ID NO: 807 — — SEQID NO: 156 H-L1-C SEQ ID NO: 679 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK192 SEQ ID NO: 3 SEQ ID NO: 805 — — SEQID NO: 156 H-L1-C SEQ ID NO: 680 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK193 SEQ ID NO: 3 SEQ ID NO: 806 — — SEQID NO: 156 H-L1-C SEQ ID NO: 681 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK194 SEQ ID NO: 1 SEQ ID NO: 808 — — SEQID NO: 156 H-L1-C SEQ ID NO: 682 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK195 SEQ ID NO: 1 SEQ ID NO: 809 — — SEQID NO: 156 H-L1-C SEQ ID NO: 683 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK196 SEQ ID NO: 1 SEQ ID NO: 810 — — SEQID NO: 156 H-L1-C SEQ ID NO: 684 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK197 SEQ ID NO: 3 SEQ ID NO: 808 — — SEQID NO: 156 H-L1-C SEQ ID NO: 685 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK198 SEQ ID NO: 3 SEQ ID NO: 809 — — SEQID NO: 156 H-L1-C SEQ ID NO: 686 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK199 SEQ ID NO: 3 SEQ ID NO: 810 — — SEQID NO: 156 H-L1-C SEQ ID NO: 687 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK200 SEQ ID NO: 1 SEQ ID NO: 811 — — SEQID NO: 156 H-L1-C SEQ ID NO: 688 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK201 SEQ ID NO: 1 SEQ ID NO: 812 — — SEQID NO: 156 H-L1-C SEQ ID NO: 689 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK202 SEQ ID NO: 1 SEQ ID NO: 263 — — SEQID NO: 156 H-L1-C SEQ ID NO: 690 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK203 SEQ ID NO: 3 SEQ ID NO: 811 — — SEQID NO: 156 H-L1-C SEQ ID NO: 266 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK204 SEQ ID NO: 3 SEQ ID NO: 812 — — SEQID NO: 156 H-L1-C SEQ ID NO: 692 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK205 SEQ ID NO: 3 SEQ ID NO: 263 — — SEQID NO: 156 H-L1-C SEQ ID NO: 693 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK206 SEQ ID NO: 3 SEQ ID NO: 800 — — SEQID NO: 156 H-L1-C SEQ ID NO: 694 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK207 SEQ ID NO: 3 SEQ ID NO: 801 — — SEQID NO: 156 H-L1-C SEQ ID NO: 695 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK208 SEQ ID NO: 1 SEQ ID NO: 804 — — SEQID NO: 156 H-L1-C SEQ ID NO: 696 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK209 SEQ ID NO: 3 SEQ ID NO: 802 — — SEQID NO: 156 H-L1-C SEQ ID NO: 697 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK210 SEQ ID NO: 1 SEQ ID NO: 807 — — SEQID NO: 156 H-L1-C SEQ ID NO: 698 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK211 SEQ ID NO: 3 SEQ ID NO: 339 — — SEQID NO: 156 H-L1-C SEQ ID NO: 699 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK212 SEQ ID NO: 1 SEQ ID NO: 339 — — SEQID NO: 156 H-L1-C SEQ ID NO: 700 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK215 SEQ ID NO: 815 SEQ ID NO: 11 — —SEQ ID NO: 156 H-L1-C SEQ ID NO: 701 — SEQ ID NO: 28 SEQ ID NO: 261 —SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK216 SEQ ID NO: 816 SEQ ID NO: 11— — SEQ ID NO: 156 H-L1-C SEQ ID NO: 702 — SEQ ID NO: 28 SEQ ID NO: 261— SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK217 SEQ ID NO: 817 SEQ ID NO:11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 703 — SEQ ID NO: 28 SEQ ID NO:261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK218 SEQ ID NO: 818 SEQ IDNO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 704 — SEQ ID NO: 28 SEQ IDNO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK219 SEQ ID NO: 819 SEQID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 705 — SEQ ID NO: 28 SEQID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK220 SEQ ID NO: 820SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 706 — SEQ ID NO: 28SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK221 SEQ ID NO:821 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 707 — SEQ ID NO:28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK222 SEQ IDNO: 822 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 708 — SEQ IDNO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK223 SEQID NO: 813 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 709 — SEQID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK224SEQ ID NO: 814 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 710 —SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267AK225 SEQ ID NO: 3 SEQ ID NO: 803 — — SEQ ID NO: 156 H-L1-C SEQ ID NO:711 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO:267 AK228 SEQ ID NO: 1 SEQ ID NO: 339 — — SEQ ID NO: 156 H-L1-C SEQ IDNO: 700 — — — — SEQ ID NO: 265 H SEQ ID NO: 265 AK231 — — — — SEQ ID NO:156 H SEQ ID NO: 156 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155H-L1-MM SEQ ID NO: 267 AK232 SEQ ID NO: 3 SEQ ID NO: 11 — — SEQ ID NO:156 H-L1-C SEQ ID NO: 667 — SEQ ID NO: 795 SEQ ID NO: 261 — SEQ ID NO:155 H-L1-MM SEQ ID NO: 712 AK233 SEQ ID NO: 1 SEQ ID NO: 691 — — SEQ IDNO: 156 H-L1-C SEQ ID NO: 713 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK234 SEQ ID NO: 3 SEQ ID NO: 691 — — SEQID NO: 156 H-L1-C SEQ ID NO: 714 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK235 SEQ ID NO: 3 SEQ ID NO: 802 — — SEQID NO: 156 H-L1-C SEQ ID NO: 697 — — — — SEQ ID NO: 265 H SEQ ID NO: 265AK252 — SEQ ID NO: 15 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO:716 SEQ ID NO: 3 SEQ ID NO: 339 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 699AK253 SEQ ID NO: 3 SEQ ID NO: 339 — — SEQ ID NO: 156 H-L1-C SEQ ID NO:699 — — — — SEQ ID NO: 265 H SEQ ID NO: 265 AK304 SEQ ID NO: 815 SEQ IDNO: 802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 717 — — — — SEQ ID NO: 265H SEQ ID NO: 265 AK305 SEQ ID NO: 815 SEQ ID NO: 802 — — SEQ ID NO: 156H-L1-C SEQ ID NO: 717 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155H-L1-MM SEQ ID NO: 267 AK306 SEQ ID NO: 816 SEQ ID NO: 802 — — SEQ IDNO: 156 H-L1-C SEQ ID NO: 718 — — — — SEQ ID NO: 265 H SEQ ID NO: 265AK307 SEQ ID NO: 816 SEQ ID NO: 802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO:718 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO:267 AK308 SEQ ID NO: 818 SEQ ID NO: 802 — — SEQ ID NO: 156 H-L1-C SEQ IDNO: 719 — — — — SEQ ID NO: 265 H SEQ ID NO: 265 AK309 SEQ ID NO: 818 SEQID NO: 802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 719 — SEQ ID NO: 28 SEQID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK310 SEQ ID NO: 819SEQ ID NO: 802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 720 — — — — SEQ IDNO: 265 H SEQ ID NO: 265 AK311 SEQ ID NO: 819 SEQ ID NO: 802 — — SEQ IDNO: 156 H-L1-C SEQ ID NO: 720 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK312 SEQ ID NO: 820 SEQ ID NO: 802 — —SEQ ID NO: 156 H-L1-C SEQ ID NO: 722 — — — — SEQ ID NO: 265 H SEQ ID NO:265 AK313 SEQ ID NO: 820 SEQ ID NO: 802 — — SEQ ID NO: 156 H-L1-C SEQ IDNO: 722 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 267 AK314 SEQ ID NO: 813 SEQ ID NO: 802 — — SEQ ID NO: 156 H-L1-CSEQ ID NO: 723 — — — — SEQ ID NO: 265 H SEQ ID NO: 265 AK315 SEQ ID NO:813 SEQ ID NO: 802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 723 — SEQ ID NO:28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK316 SEQ IDNO: 1 SEQ ID NO: 802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 674 — SEQ IDNO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK325 SEQID NO: 815 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 701 — SEQID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK326SEQ ID NO: 816 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 702 —SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267AK327 SEQ ID NO: 818 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ ID NO:704 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO:267 AK328 SEQ ID NO: 819 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQ IDNO: 705 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 267 AK329 SEQ ID NO: 820 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-C SEQID NO: 706 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQID NO: 267 AK330 SEQ ID NO: 813 SEQ ID NO: 11 — — SEQ ID NO: 156 H-L1-CSEQ ID NO: 709 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MMSEQ ID NO: 267 AK349 SEQ ID NO: 813 SEQ ID NO: 807 — — SEQ ID NO: 156H-L1-C SEQ ID NO: 728 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155H-L1-MM SEQ ID NO: 267 AK350 SEQ ID NO: 813 SEQ ID NO: 797 — — SEQ IDNO: 156 H-L1-C SEQ ID NO: 729 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK351 SEQ ID NO: 813 SEQ ID NO: 798 — —SEQ ID NO: 156 H-L1-C SEQ ID NO: 730 — SEQ ID NO: 28 SEQ ID NO: 261 —SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK352 SEQ ID NO: 813 SEQ ID NO:724 SEQ ID NO: 156 H-L1-C SEQ ID NO: 731 — SEQ ID NO: 28 SEQ ID NO: 261— SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK353 SEQ ID NO: 813 SEQ ID NO:725 SEQ ID NO: 156 H-L1-C SEQ ID NO: 732 — SEQ ID NO: 28 SEQ ID NO: 261— SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK354 SEQ ID NO: 813 SEQ ID NO:536 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 733 — SEQ ID NO: 28 SEQ ID NO:261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK355 SEQ ID NO: 813 SEQ IDNO: 537 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 734 — SEQ ID NO: 28 SEQ IDNO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK357 SEQ ID NO: 813 SEQID NO: 502 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 735 — SEQ ID NO: 28 SEQID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK358 SEQ ID NO: 813SEQ ID NO: 503 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 736 — SEQ ID NO: 28SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK359 SEQ ID NO:813 SEQ ID NO: 492 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 737 — SEQ ID NO:28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK360 SEQ IDNO: 813 SEQ ID NO: 493 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 738 — SEQ IDNO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK361 SEQID NO: 813 SEQ ID NO: 416 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 739 — SEQID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK362SEQ ID NO: 813 SEQ ID NO: 417 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 740 —SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267AK363 SEQ ID NO: 813 SEQ ID NO: 418 — — SEQ ID NO: 156 H-L1-C SEQ ID NO:741 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ ID NO:267 AK364 SEQ ID NO: 813 SEQ ID NO: 419 — — SEQ ID NO: 156 H-L1-C SEQ IDNO: 742 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MM SEQ IDNO: 267 AK365 SEQ ID NO: 813 SEQ ID NO: 350 — — SEQ ID NO: 156 H-L1-CSEQ ID NO: 743 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MMSEQ ID NO: 267 AK366 SEQ ID NO: 813 SEQ ID NO: 351 — — SEQ ID NO: 156H-L1-C SEQ ID NO: 744 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155H-L1-MM SEQ ID NO: 267 AK367 SEQ ID NO: 813 SEQ ID NO: 352 — — SEQ IDNO: 156 H-L1-C SEQ ID NO: 745 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ IDNO: 155 H-L1-MM SEQ ID NO: 267 AK368 SEQ ID NO: 813 SEQ ID NO: 353 — —SEQ ID NO: 156 H-L1-C SEQ ID NO: 746 — SEQ ID NO: 28 SEQ ID NO: 261 —SEQ ID NO: 155 H-L1-MM SEQ ID NO: 267 AK317 SEQ ID NO: 1 SEQ ID NO: 802— — SEQ ID NO: 156 H-L1-C SEQ ID NO: 674 — SEQ ID NO: 28 SEQ ID NO: 826— SEQ ID NO: 155 H-L1-MM SEQ ID NO: 828 AK324 SEQ ID NO: 1 SEQ ID NO:802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 674 — SEQ ID NO: 28 SEQ ID NO:827 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 829 AK341 SEQ ID NO: 3 SEQ IDNO: 802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 726 — SEQ ID NO: 28 SEQ IDNO: 826 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 830 AK342 SEQ ID NO: 3 SEQID NO: 802 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 726 — SEQ ID NO: 28 SEQID NO: 827 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 829

Also generated are masked IL-15 polypeptide constructs that include anIL-15 polypeptide or functional fragment thereof, a masking moiety, afirst half-life extension domain, and a second half-life extensiondomain, such as albumin, an antibody or fragment thereof (e.g., an Fcregion, heavy chain, and/or light chain), an albumin-binding peptide, anIgG-binding peptide, or a polyamino acid sequence. The masking moiety islinked to the first half-life extension domain, the IL-15 polypeptide orfunctional fragment thereof is linked to the second half-life extensiondomain, and the first half-life extension domain and the secondhalf-life extension domain contain modifications promoting theassociation of the first and the second half-life extension domain. Someof the constructs also include a linker that links the masking moiety tothe first half-life extension domain, and/or a linker that links theIL-15 polypeptide or functional fragment thereof to the second half-lifeextension domain. The first and second half-life extension domain ofsome of the constructs are also linked. In some constructs, the firstand second half-life extension domain of some of the constructs arelinked by a linker. Some of the constructs include a cleavable peptidein the linker linking the masking moiety to the first half-lifeextension domain and/or the linker linking the IL-15 polypeptide orfunctional fragment thereof to the second half-life extension domain,thereby resulting in an activatable masked IL-15 polypeptide construct.The masked IL-15 polypeptide constructs that do not include a cleavablepeptide in either the linker that links the IL-15 polypeptide orfunctional fragment thereof to the second half-life extension domain orthe linker that links the masking moiety to the first half-lifeextension domain are also referred to as non-activatable masked IL-15polypeptide constructs or non-activatable IL-15 polypeptide constructsbecause they do not include a cleavable peptide. The structure andcomposition of exemplary IL-15 polypeptide constructs are provided inTable 9.

TABLE 9 Cytokine or Structure functional Half-life (N- to C- Constructfragment Masking moiety extension terminal Amino Acid # thereof (C)Linker (L1) (MM) Linker (L2) domain (H) direction) Sequence 3033 — SEQID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 167 SEQ IDNO: 11 — — SEQ ID NO: 156 H-L1-C 3034 — SEQ ID NO: 28 SEQ ID NO: 10 —SEQ ID NO: 155 MM-L1-H SEQ ID NO: 167 SEQ ID NO: 11 — — SEQ ID NO: 156C-L1-H 3035 — SEQ ID NO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 MM-L1-H SEQID NO: 167 SEQ ID NO: 11 — — SEQ ID NO: 156 C-L1-H 3036 — SEQ ID NO: 28SEQ ID NO: 232 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 167 SEQ ID NO: 11 — —SEQ ID NO: 156 H-L1-C 3037 — SEQ ID NO: 28 SEQ ID NO: 233 — SEQ ID NO:155 MM-L1-H SEQ ID NO: 167 SEQ ID NO: 11 — — SEQ ID NO: 156 C-L1-H 3038SEQ ID NO: 28 SEQ ID NO: 233 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 167 SEQID NO: 11 — — SEQ ID NO: 156 H-L1-C AK243 SEQ ID NO: 167 SEQ ID NO: 668— — SEQ ID NO: 156 H-L1-C SEQ ID NO: 715 — — — — SEQ ID NO: 265 H SEQ IDNO: 265 AK247 SEQ ID NO: 167 SEQ ID NO: 845 SEQ ID NO: 156 H-L1-C SEQ IDNO: 747 — SEQ ID NO: 799 SEQ ID NO: 261 — SEQ ID NO: 156 H-L1-MM SEQ IDNO: 671 AK248 SEQ ID NO: 167 SEQ ID NO: 668 — — SEQ ID NO: 156 H-L1-CSEQ ID NO: 715 — SEQ ID NO: 28 SEQ ID NO: 261 — SEQ ID NO: 155 H-L1-MMSEQ ID NO: 267 AK248b SEQ ID NO: 167 SEQ ID NO: 668 — — SEQ ID NO: 156H-L1-C SEQ ID NO: 715 — SEQ ID NO: 799 SEQ ID NO: 261 — SEQ ID NO: 156H-L1-MM SEQ ID NO: 671 AK249 SEQ ID NO: 167 SEQ ID NO: 355 SEQ ID NO:156 H-L1-C SEQ ID NO: 748 — SEQ ID NO: 799 SEQ ID NO: 261 — SEQ ID NO:156 H-L1-MM SEQ ID NO: 671 AK250 SEQ ID NO: 167 SEQ ID NO: 354 SEQ IDNO: 823 SEQ ID NO: 27 SEQ ID NO: 156 H-L1-C-L2-MM SEQ ID NO: 749 — SEQID NO: 799 SEQ ID NO: 261 — SEQ ID NO: 156 H-L1-MM SEQ ID NO: 671 AK251SEQ ID NO: 167 SEQ ID NO: 354 SEQ ID NO: 824 SEQ ID NO: 27 SEQ ID NO:156 H-L1-C-L2-MM SEQ ID NO: 750 — SEQ ID NO: 799 SEQ ID NO: 261 — SEQ IDNO: 156 H-L1-MM SEQ ID NO: 671 AK418 SEQ ID NO: 167 SEQ ID NO: 348 — —SEQ ID NO: 156 H-L1-C SEQ ID NO: 751 — SEQ ID NO: 799 SEQ ID NO: 261 —SEQ ID NO: 156 H-L1-MM SEQ ID NO: 671 AK419 SEQ ID NO: 167 SEQ ID NO:668 SEQ ID NO: 823 SEQ ID NO: 27 SEQ ID NO: 156 H-L1-C-L2-MM SEQ ID NO:752 — SEQ ID NO: 799 SEQ ID NO: 261 — SEQ ID NO: 156 H-L1-MM SEQ ID NO:671 AK420 SEQ ID NO: 167 SEQ ID NO: 668 SEQ ID NO: 824 SEQ ID NO: 27 SEQID NO: 156 H-L1-C-L2-MM SEQ ID NO: 753 — SEQ ID NO: 799 SEQ ID NO: 261 —SEQ ID NO: 156 H-L1-MM SEQ ID NO: 671 AK421 SEQ ID NO: 167 SEQ ID NO:349 — — SEQ ID NO: 156 H-L1-C SEQ ID NO: 754 — SEQ ID NO: 799 SEQ ID NO:261 — SEQ ID NO: 156 H-L1-MM SEQ ID NO: 671 AK399 SEQ ID NO: 167 SEQ IDNO: 320 SEQ ID NO: 823 SEQ ID NO: SEQ ID NO: 156 H-L1-C-L2-MM SEQ ID NO:758 321 — SEQ ID NO: 799 SEQ ID NO: 261 — SEQ ID NO: 156 H-L1-MM SEQ IDNO: 671 AK405 SEQ ID NO: 167 SEQ ID NO: 320 SEQ ID NO: 823 SEQ ID NO:SEQ ID NO: 156 H-L1-C-L2-MM SEQ ID NO: 759 322 — SEQ ID NO: 799 SEQ IDNO: 261 — SEQ ID NO: 156 H-L1-MM SEQ ID NO: 671 AK400 SEQ ID NO: 167 SEQID NO: 349 SEQ ID NO: 824 SEQ ID NO: 30 SEQ ID NO: 156 H-L1-C-L2-MM SEQID NO: 760 — SEQ ID NO: 799 SEQ ID NO: 261 — SEQ ID NO: 156 H-L1-MM SEQID NO: 671 AK404 SEQ ID NO: 167 SEQ ID NO: 349 SEQ ID NO: 823 SEQ ID NO:30 SEQ ID NO: 156 H-L1-C-L2-MM SEQ ID NO: 761 — SEQ ID NO: 799 SEQ IDNO: 261 — SEQ ID NO: 156 H-L1-MM SEQ ID NO: 671

Also generated are masked IL-2 polypeptide constructs that include anIL-2 polypeptide or functional fragment thereof, a first masking moiety,a second masking moiety, a first half-life extension domain, and asecond half-life extension domain, such as albumin, an antibody orfragment thereof (e.g., an Fc region, heavy chain, and/or light chain),an albumin-binding peptide, an IgG-binding peptide, or a polyamino acidsequence. The first masking moiety is linked to the first half-lifeextension domain, the second masking moiety is linked to the IL-2polypeptide or functional fragment thereof, either the second maskingmoiety or the IL-2 polypeptide or functional fragment thereof is linkedto the second half-life extension domain, and the first half-lifeextension domain and the second half-life extension domain containmodifications promoting the association of the first and secondhalf-life extension domain. Some of the constructs also include a linkerthat links the first masking moiety to the first half-life extensiondomain, and/or a linker that linkers the second masking moiety to theIL-2 polypeptide or functional fragment thereof. The first and secondhalf-life extension domain of some of the constructs are also linked. Insome constructs, the first and second half-life extension domain of someof the constructs are linked by a linker. Some of the constructs includea cleavable peptide in the linker linking the first masking moiety tothe first half-life extension domain, and/or include a cleavable peptidein the linker linking the second masking moiety to the IL-2 polypeptideor functional fragment thereof, thereby resulting in an activatablemasked IL-2 polypeptide construct. The masked IL-2 polypeptideconstructs that do not include a cleavable peptide in either the linkerthat links the first masking moiety to the first half-life extensiondomain or the linker linking the second masking moiety to the IL-2polypeptide or functional fragment thereof are also referred to asnon-activatable masked IL-2 polypeptide constructs or non-activatableIL-2 polypeptide constructs because they do not include a cleavablepeptide. The structure and composition of exemplary IL-2 polypeptideconstructs are provided in Table 10.

TABLE 10 Cytokine or Structure functional Half-life (N- to C- Constructfragment Masking moiety extension terminal # thereof (C) Linker (L1)(MM) Linker (L2) domain (H) direction) 4000 — SEQ ID NO: 28 SEQ ID NO:10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 1 SEQ ID NO: 11 SEQ ID NO: 9 SEQID NO: 15 SEQ ID NO: 156 H-L1-C-L2-MM 4001 — SEQ ID NO: 28 SEQ ID NO: 10— SEQ ID NO: 155 H-L1-MM SEQ ID NO: 3 SEQ ID NO: 11 SEQ ID NO: 9 SEQ IDNO: 16 SEQ ID NO: 156 H-L1-C-L2-MM 4002 — SEQ ID NO: 28 SEQ ID NO: 10 —SEQ ID NO: 155 H-L1-MM SEQ ID NO: 4 SEQ ID NO: 11 SEQ ID NO: 9 SEQ IDNO: 17 SEQ ID NO: 156 H-L1-C-L2-MM 4003 — SEQ ID NO: 28 SEQ ID NO: 10 —SEQ ID NO: 155 MM-L1-H SEQ ID NO: 5 SEQ ID NO: 11 SEQ ID NO: 9 SEQ IDNO: 18 SEQ ID NO: 156 MM-L2-C-L1-H 4004 — SEQ ID NO: 28 SEQ ID NO: 10 —SEQ ID NO: 155 MM-L1-H SEQ ID NO: 6 SEQ ID NO: 11 SEQ ID NO: 9 SEQ IDNO: 19 SEQ ID NO: 156 MM-L2-C-L1-H 4005 — SEQ ID NO: 28 SEQ ID NO: 10 —SEQ ID NO: 155 MM-L1-H SEQ ID NO: 7 SEQ ID NO: 11 SEQ ID NO: 9 SEQ IDNO: 15 SEQ ID NO: 156 MM-L2-C-L1-H 4006 — SEQ ID NO: 28 SEQ ID NO: 10 —SEQ ID NO: 155 H-L1-MM SEQ ID NO: 8 SEQ ID NO: 11 SEQ ID NO: 9 SEQ IDNO: 16 SEQ ID NO: 156 H-L1-C-L2-MM

Also generated are masked IL-15 polypeptide constructs that include anIL-15 polypeptide or functional fragment thereof, a first maskingmoiety, a second masking moiety, a first half-life extension domain, anda second half-life extension domain, such as albumin, an antibody orfragment thereof (e.g., an Fc region, heavy chain, and/or light chain),an albumin-binding peptide, an IgG-binding peptide, or a polyamino acidsequence. The first masking moiety is linked to the first half-lifeextension domain, the second masking moiety is linked to the IL-15polypeptide or functional fragment thereof, either the second maskingmoiety or the IL-15 polypeptide or functional fragment thereof is linkedto the second half-life extension domain, and the first half-lifeextension domain and the second half-life extension domain containmodifications promoting the association of the first and secondhalf-life extension domain. Some of the constructs also include a linkerthat links the first masking moiety to the first half-life extensiondomain, and/or a linker that linkers the second masking moiety to theIL-15 polypeptide or functional fragment thereof. The first and secondhalf-life extension domain of some of the constructs are also linked. Insome constructs, the first and second half-life extension domain of someof the constructs are linked by a linker. Some of the constructs includea cleavable peptide in the linker linking the first masking moiety tothe first half-life extension domain, and/or include a cleavable peptidein the linker linking the second masking moiety to the IL-15 polypeptideor functional fragment thereof, thereby resulting in an activatablemasked IL-15 polypeptide construct. The masked IL-15 polypeptideconstructs that do not include a cleavable peptide in either the linkerthat links the first masking moiety to the first half-life extensiondomain or the linker linking the second masking moiety to the IL-15polypeptide or functional fragment thereof are also referred to asnon-activatable masked IL-15 polypeptide constructs or non-activatableIL-15 polypeptide constructs because they do not include a cleavablepeptide. The structure and composition of exemplary IL-2 polypeptideconstructs are provided in Table 11.

TABLE 11 Cytokine or Structure functional Half-life (N- to C- Constructfragment Masking moiety extension terminal # thereof (C) Linker (L1)(MM) Linker (L2) domain (H) direction) 3034 — SEQ ID NO: 28 SEQ ID NO:10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 167 SEQ ID NO: 11 SEQ ID NO: 232SEQ ID NO: 235 SEQ ID NO: 156 H-L1-C-L2-MM 3035 — SEQ ID NO: 28 SEQ IDNO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 167 SEQ ID NO: 11 SEQ ID NO:233 SEQ ID NO: 235 SEQ ID NO: 156 H-L1-C-L2-MM 3036 — SEQ ID NO: 28 SEQID NO: 10 — SEQ ID NO: 155 H-L1-MM SEQ ID NO: 167 SEQ ID NO: 11 SEQ IDNO: 234 SEQ ID NO: 235 SEQ ID NO: 156 H-L1-C-L2-MM 3038 — SEQ ID NO: 28SEQ ID NO: 10 — SEQ ID NO: 155 MM-L1-H SEQ ID NO: 167 SEQ ID NO: 11 SEQID NO: 232 SEQ ID NO: 235 SEQ ID NO: 156 MM-L2-C-L1-H 3039 — SEQ ID NO:28 SEQ ID NO: 10 — SEQ ID NO: 155 MM-L1-H SEQ ID NO: 167 SEQ ID NO: 11SEQ ID NO: 233 SEQ ID NO: 235 SEQ ID NO: 156 MM-L2-C-L1-H 3040 — SEQ IDNO: 28 SEQ ID NO: 10 — SEQ ID NO: 155 MM-L1-H SEQ ID NO: 167 SEQ ID NO:11 SEQ ID NO: 234 SEQ ID NO: 235 SEQ ID NO: 156 MM-L2-C-L1-H

Example 2: In Vitro Characterization of Masked IL-2 and IL-15Polypeptides

The masked IL-2 polypeptide constructs and masked IL-15 polypeptideconstructs generated in Example 1 are characterized using severalcellular and functional assays in vitro.

Production

Plasmids encoding the constructs (e.g., masked IL-2 polypeptideconstructs and masked IL-15 polypeptide constructs) were transfectedinto either Expi293 cells (Life Technologies A14527) or HEK293-6E cells(National Research Council; NRC). Transfections were performed using 1mg of total DNA using PEIpro (Polyplus Transfection, 115-100) in a 1:1ratio with the total DNA. The DNA and PEI were each added to 50 mL ofOptiMem (Life Technologies 31985088) medium and sterile filtered. TheDNA and PEI were combined for 10 minutes and added to the Expi293 cellswith a cell density of 1.8-2.8×10⁶ cells/mL or 0.85-1.20×10⁶ cells/m,for expi293 cells or HEK293 cells, respectively, and a viability of atleast 95%. The HEK293-6E transfection was performed with a cell densityof and a viability of at least 95%, following the same protocol used forthe Expi293 transfections. After 5-7 days, the cells were pelleted bycentrifugation at 3000×g and the supernatant was filtered through a 0.2μm membrane. Protein A resin (CaptivA, Repligen CA-PRI-0005) was addedto the filtered supernatant and incubated for at least 2 hours at 4° C.with shaking. The resin was packed into a column, washed with 15 columnvolumes of 20 mM citrate, pH 6.5, and then washed with 15 column volumesof 20 mM citrate, 500 mM sodium chloride, pH 6.5. The bound protein waseluted from the column with 20 mM citrate, 100 mM NaCl, pH 2.9.

The titer (mg/L) of exemplary constructs produced, including parental(e.g., non-masked) and masked constructs, is provided in Table 12,below.

TABLE 12 Construct ID Titer (mg/L) AK032 5.8 AK033 9.6 AK034 13.9 AK03516.7 AK036 25 AK037 11.1 AK039 3.5 AK040 0.7 AK042 1.9 AK043 1.1 AK04415 AK045 9.3 AK046 12.5 AK047 18.5 AK048 24 AK049 12.2 AK050 12.8 AK05111.9 AK052 10 AK053 15.2 AK054 11.9 AK055 13.2 AK056 9.2 AK057 10.8AK058 13.5 AK059 3.7 AK060 1.2 AK061 3.5 AK062 0.6 AK248 47.7 AK063 3.5AK064 1.5 AK065 3.2 AK066 3.5 AK076 1.4 AK077 1.5 AK078 4.4 AK079 4.3AK080 2.3 AK081 23.5 AK083 3.3 AK084 3.2 AK085 2.1 AK086 3.2 AK087 3.2AK088 41 AK090 14.8 AK092 6.3 AK094 17.1 AK106 10.5 AK107 0 AK109 12.6AK110 23.8 AK111 12.7 AK112 21.6 AK113 25.3 AK114 29 AK115 15 AK163 7.5AK164 4 AK165 13.5 AK166 17.1 AK167 56.4 AK168 36.1 AK184 21.6 AK18812.8 AK203 83.2 AK209 27.3 AK211 43.8 AK212 18.2 AK225 44.1 AK226 20.2AK227 27.4 AK228 20.1 AK231 19.3 AK233 36.4 AK234 33.3 AK235 35.9 AK25268 AK253 41.4 AK304 19.9 AK305 53.2 AK306 29.3 AK307 62.9 AK308 74.5AK309 90.8 AK310 44 AK311 64.9 AK312 154 AK313 81.2 AK314 60 AK315 59.8AK316 69.2 AK325 3.2 AK326 33.1 AK327 68.5 AK328 28.8 AK329 181 AK330 51AK341 58 AK342 24 AK349 39.6 AK350 7.8 AK351 9.3 AK352 9.9 AK353 11AK354 9.8 AK355 13.7 AK357 13.1 AK358 12.4 AK359 10.4 AK360 11.1 AK36113.7 AK362 9.3 AK363 13.2 AK364 7.9 AK365 10.9 AK366 8.3 AK367 10.3AK368 7.1

SDS-PAGE Analysis

For SDS-PAGE analysis, protein samples were made with 4× Laemmli samplebuffer (BioRad Catalog Number 1610747). For the reduced samples, 0.1 MBond Breaker TCEP Solution (Thermo Scientific 77720) was added and thesamples were heated for 5 minutes at 65° C. The proteins were loadedinto a 12-well NuPage 4-12% Bis-Tris Protein Gel (Invitrogen NP0322BOX),with 4 ng of protein loaded per well. The gel was stained usingSimplyBlue SafeStain (Invitrogen LC6065).

As depicted in FIG. 8, SDS-PAGE analysis was performed on theflow-through (FT) samples (i.e., proteins that did not bind to theProtein A column) and the eluted (E) samples (i.e., proteins that boundto the Protein A column and were eluted from it) following productionand purification of exemplary constructs (AK304, AK305, AK307, AK308,AK309, AK310, AK311, AK312, AK313, AK314, and AK315). This exemplarydata demonstrates that constructs as described herein can besuccessfully produced and purified.

Reporter Bioassays

Reporter bioassays are performed on masked IL-2 polypeptide constructsand masked IL-15 polypeptide constructs, along with non-masked parentalconstructs or other controls, to monitor activation of a downstreampathway, such as the JAK-STAT pathway.

In some studies, HEK-Blue IL-2 reporter cells (Invivogen) were used totest activation of the JAK-STAT pathway in accordance with the followingmethod. HEK-Blue IL-2 cells passage 6 (p6) (97% live) were washed 2×with assay medium (DMEM+10% heat-inactivated FBS), plated in 3 plated at5e4 cells/well in 150 uL of assay medium, and rested in assay medium forabout 2 hours to allow adherence to plate. Each construct tested wasdiluted to 300 pM in assay medium, then diluted 1:2 down the plate. 50uL of each dilution was added, for a final starting concentration of 75pM. HEK-Blue IL-2 cell supernatant was harvested after 24 hours, anincubated with Quantiblue (180 uL+20 uL supernatant), plus 3 wells/plateof assay medium, at 37 deg C. for 1 hour. The absorbance was read usinga Biotek Neo2 at 625 nm. In one study, the exemplary masked IL-15polypeptide construct AK248 was tested in accordance with this protocol,with or without prior exposure to an MMP10 protease, along withrecombinant human IL-15 (rhIL-15) as a positive control. As shown inFIGS. 22A and 22B, there was no detectable activation of the JAK-STATpathway when using the masked IL-15 polypeptide construct AK248 (withoutprotease cleavage), but following cleavage by an activating protease,strong levels of activation of the JAK-STAT pathway were observed. Thisdemonstrates that an exemplary IL-15 polypeptide can be effectivelymasked and also activated through protease cleavage.

In some studies, CTLL2 cells were used to test activation of theJAK-STAT pathway in accordance with the following method. CTLL2 cellswere plated at 40,000 cell per well in RPMI with 10% FBS. Dilutions ofthe constructs of interest (e.g., the masked IL-15 polypeptide constructAK248, with or without prior exposure to an MMP protease, or a positivecontrol such as rhIL-15) were added and incubated at 37 degrees. After 6hours, the Bio-Glo reagent was added and luminescence measured with aBioTek Synergy Neo2 plate reader.

Receptor Binding

The binding of the masked IL-2 polypeptide constructs and the maskedIL-15 polypeptide constructs generated in Example 1 is assessed. For themasked IL-2 polypeptide constructs, in some experiments, ELISA platesare coated with a receptor subunit, such as IL-2Rα (also referred to asCD25), IL-2Rβ (also referred to as CD122), or IL-2R7 (also referred toas CD132), or combinations thereof. For the masked IL-15 polypeptideconstructs, in some experiments, ELISA plates are coated with a receptorsubunit, such as IL-15Rα, IL-2Rβ (also referred to as CD122), or IL-2Rγ(also referred to as CD132), or combinations thereof. Dilutions ofmasked IL-2 polypeptide constructs or masked IL-15 polypeptideconstructs are allowed to bind to the receptor subunit(s) and aredetected using an anti-huFc-HRP detection antibody. The binding of themasked IL-2 polypeptide constructs and masked IL-15 polypeptideconstructs is determined in conditions with and without proteasecleavage.

On-Cell Receptor Binding

The on-cell receptor binding of the masked IL-2 polypeptide constructsand the masked IL-15 polypeptide constructs generated in Example 1 isassessed. Dilutions of masked IL-2 polypeptide constructs or IL-15polypeptide constructs are allowed to bind to peripheral bloodlymphocytes or tissue culture cells, such as CTLL2 cells and aredetected by fluorescence activated cell sorting (FACS) using ananti-huFc-FITC or anti-albumin-FITC detection antibody. The binding ofthe masked IL-2 polypeptide constructs and IL-15 polypeptide constructsis determined in conditions with and without protease cleavage.

Receptor Binding Affinity

The binding affinity of the masked IL-2 polypeptide constructs and themasked IL-15 polypeptide constructs generated in Example 1 is assessed.For example, surface plasmon resonance (SPR) is performed at roomtemperature and/or 37° C. The IL-2 receptors (e.g., IL-2Rα, IL-2Rβ, orIL-2Rγ, or combinations thereof) are coupled to CMS chips (GEHealthcare) via EDC/NHS chemistry. The IL-15 receptors (e.g., IL-15Rα,IL-2Rβ, or IL-2Rγ, or combinations thereof) are coupled to CMS chips (GEHealthcare) via EDC/NHS chemistry. Masked IL-2 polypeptide constructs ormasked IL-15 polypeptide constructs are flowed over the chips at a rangeof concentrations to obtain dissociation constants for on- andoff-rates. The binding affinity of the masked IL-2 polypeptideconstructs and the IL-15 polypeptide constructs is determined inconditions with and without protease cleavage.

For some SPR studies testing binding of masked and non-masked IL-2polypeptide constructs, Reichert Carboxymethyl Dextran Hydrogel SurfaceSensor Chips were coated and immobilized with the construct of interest(e.g., a masked IL-2 polypeptide construct or non-masked IL-2polypeptide construct) at 30 ug/ml in 10 mM Sodium Acetate, pH 5.0diluted 1:1 in EDC and NHS. Dilutions of CD25-Fc or Fc-CD122 in PBS(CD25: 16 nM, 8 nM, 4 nM, 2 nM, 1 nM and CD122: 500 nM, 250 nM, 125 nM,62.5 nM, 31.25 nM) were prepared. Using a Reichert 4Channel SPR,dilutions of CD25 or CD122 were flowed over the clips with theimmobilized construct to determine the on rate at 25 degrees C. Atequilibrium (approximately 3-4 minutes), the flow buffer was changed toPBS, to determine the off rates over 1 minute. Between each run the chipwas regenerated with 10 mM glycine, pH 2.0. A similar approach is takento test binding of masked and unmasked IL-15 polypeptide constructs toappropriate binding partners at appropriate concentrations in accordancewith the teachings and examples herein.

FIGS. 9A-9D depict results from SPR analysis that tested the binding ofexemplary masked IL-2 polypeptide constructs (AK215 and AK216) toCD25-Fc. FIG. 9A depicts the interaction between AK215 and CD25-Fc, FIG.9B depicts the interaction between AK216 and CD25-Fc, and FIG. 9Cdepicts the interaction between a recombinant human IL2 (rhIL2) controland CD25-Fc. FIG. 9D provides a table summarizing the data obtained forthe association constant (ka), dissociation constant (kd), equilibriumdissociation constant (KD), as well as the Chi² value and U-value foreach interaction. These results demonstrate that these exemplary maskedIL-2 polypeptide constructs did not demonstrate detectable binding toCD25-Fc, while the rhIL2 control did demonstrate detectable binding.

FIGS. 10A-10D depict results from SPR analysis that tested the bindingof exemplary masked IL-2 polypeptide constructs (AK216 and AK218) toCD122-Fc. FIG. 10A depicts the interaction between AK216 and CD122-Fc,FIG. 10B depicts the interaction between AK218 and CD122-Fc, and FIG.10C depicts the interaction between a recombinant human IL2 (rhIL2)control and CD122-Fc. FIG. 10D provides a table summarizing the dataobtained for the association constant (ka), dissociation constant (kd),equilibrium dissociation constant (KD), as well as the Chi² value andU-value for each interaction. These results demonstrate that theseexemplary masked IL-2 polypeptide constructs did not demonstratedetectable binding to CD122-Fc, while the rhIL2 control did demonstratedetectable binding. Additional exemplary SPR data is provided below inTable 13 for various constructs tested, including masked and non-maskedconstructs. For some structures, when applicable, the KD was determinedfor the construct with or without having been previously cleaved by aprotease.

TABLE 13 KD for CD25 KD for CD122 KD for CD122 (without (without (afterCon- protease protease protease struct cleavage) cleavage) cleavage)rhIL2 1.2 nM 124 nM N/A AK032 1.76 nM 260 nM N/A AK033 No bindingdetected 368 nM* N/A AK034 No binding detected Not determined N/A AK035No binding detected 110 nM N/A AK042 No binding detected 4.1 nM N/AAK049 No binding detected 4.67 nM N/A AK056 No binding detected Notdetermined N/A AK076 2.28 nM No binding detected AK077 4.77 nM Nobinding detected AK078 3.41 nM No binding detected AK081 1.66 nM 489 nM*N/A AK109 1.67 nM No binding detected 118 nM AK110 0.911 nM No bindingdetected 195 nM AK111 0.4 nM No binding detected 235 nM AK112 0.724 nMNo binding detected No binding detected AK113 No binding detected 191 nM74.3 nM AK114 No binding detected 10.2 nM 13.8 nM AK168 No bindingdetected Not determined 175 nM AK215 No binding detected AK216 Nobinding detected AK217 1.9 nM AK218 Weak binding AK219 Weak bindingAK220 Weak or no binding detected AK221 Weak binding AK222 Weak or nobinding detected AK223 No binding detected AK224 No binding detected

Cleavage

The cleavage rate of the masked IL-2 polypeptide constructs is assessedby conducting receptor-binding assays, as described above, afterincubation of the masked IL-2 peptide constructs in the presence orabsence of a protease, and with the protease, if any, inactivated atvarious time points, such as by the addition of EDTA. The cleavage rateof the masked IL-15 polypeptide constructs is assessed by conductingreceptor-binding assays, as described above, after incubation of themasked IL-15 peptide constructs in the presence or absence of aprotease, and with the protease, if any, inactivated at various timepoints, such as by the addition of EDTA. The cleavage rate is alsoassessed using reducing and non-reducing polyacrylamide gelelectrophoresis (PAGE) and by mass spectrometry whole mass and peptidemap analyses. The cleavage rate is also assessed using an ex vivo assayin which the masked IL-2 polypeptide constructs or the masked IL-15polypeptide constructs are exposed to human, mouse, or cynomolgus monkeyperipheral blood lymphocytes, or normal human tissue or human tumortissue.

For some protease activation studies, MMP10 was diluted to 50 ng/uL inMMP cleavage buffer and activated with 1 mM APMA for 2 h at 37° C. 5 μLof protease (250 ng total) of the activated protease was incubated with1 uM of masked cytokine constructs (e.g., masked IL-2 polypeptideconstructs) and incubated at 37 degrees for 2 hours. Cleavage wasassessed by SDS-PAGE using AnykD™ Criterion™ TGX Stain-Free™ ProteinGels. A similar approach is taken to test cleavage by other proteases.

FIG. 11A depicts an exemplary structure of a masked IL-2 polypeptideprior to (left) and after (right) cleavage by a protease, such as aprotease associated with the tumor environment. FIG. 11B depictsSDS-PAGE analysis of an exemplary masked IL-2 polypeptide construct thatwas incubated in the absence (left lane) or presence (right lane) of theMMP10 protease.

Proliferation

Proliferation of IL-2 and IL-15 responsive tissue culture cell lines,such as CTLL2, YT, TF1B, LGL, HH, and CT6, following treatment with themasked IL-2 polypeptide constructs or the masked IL-15 polypeptideconstructs generated in Example 1 is assessed. For experiments involvingthe masked IL-2 polypeptide constructs, cells are plated in 96 welltissue culture plates in media lacking IL-2 for 2-4 hours and thentreated with the masked IL-2 polypeptide constructs at variousconcentrations. For experiments involving the masked IL-15 polypeptideconstructs, cells are plated in 96 well tissue culture plates in medialacking IL-15 for 2-4 hours and then treated with the masked IL-15polypeptide constructs at various concentrations. After incubation at 37degrees for 24-48 hours, the cell number is determined by the additionof MTS, alamar blue, luciferase, or a similar metabolic detectionreagent, and the colorimetric, fluorescent or luciferase readoutdetected by a plate spectrophotometer reader.

The proliferation of immune cells following treatment with the maskedIL-2 polypeptide constructs or the masked IL-15 polypeptide constructsgenerated in Example 1 is also assessed. Human, mouse, or cynomolgusperipheral blood mononuclear cells (PBMCs) are treated with theconstructs at various concentrations, and the proliferation of celltypes, such as Natural Killer (NK) cells, CD8+ T cells, CD4+ T cells,and/or Treg cells, is determined by staining for the particular celltype and analysis via fluorescence activated cell sorting (FACS). Insome experiments, some PBMCs are treated with controls for comparison.In some experiments, some PBMCs are treated with aldesleukin as acontrol for the masked IL-2 polypeptide treatment. In some experiments,the masked IL-2 polypeptide constructs and the masked IL-15 polypeptideconstructs are tested in conditions with and without protease cleavage(e.g., activation). In some experiments, the NK cells are stained asCD45+CD3−CD56+, the CD8+ T cells are stained as CD45+CD3+CD8+, the CD4+T cells are stained as CD45+CD3+CD4+CD25-, and the Treg cells arestained as CD45+CD3+CD4+CD25+FOXP3+. In some experiments, the PBMCs aretreated for a period of five days. In some experiments, the PBMCs arealso stained with Ki67, a marker of cell proliferation. In someexperiments, the PBMCs are labeled with CFSE (Sigma-Aldrich) prior totreatment and proliferation is measured by determining the extent ofCFSE dilution. In some experiments, each construct, as well asaldesleukin and/or other controls, is administered at one or moreconcentrations, such as one or more concentrations ranging from 0.0001nM to 500 nM.

STAT5 Activation

The activation of Signal Transducer and Activator of Transcription 5(STAT5) following treatment with the masked IL-2 polypeptide constructsor the masked IL-15 polypeptide constructs generated in Example 1 isalso assessed. PBMCs are treated with the constructs for a specifiedperiod of time and are then immediately fixed to preserve thephosphorylation status of proteins, such as STAT5. In some experiments,some PBMCs are treated with controls for comparison. In someexperiments, some PBMCs are treated with aldesleukin as a control forthe masked IL-2 polypeptide treatment. In some experiments, the maskedIL-2 polypeptide constructs and the masked IL-15 polypeptide constructsare tested in conditions with and without protease cleavage (e.g.,activation). In some experiments, the PBMCs are treated for 10 minutes,15 minutes, 20 minutes, or 25 minutes. In some experiments, eachconstruct, as well as aldesleukin and/or other controls, is administeredat one or more concentrations, such as one or more concentrationsranging from 0.0001 nM to 500 nM. In some experiments, the fixed andpermeabilized PBMCs are then stained with an antibody specific forphosphorylated STAT5 (phospho-STAT5) and are analyzed by flow cytometry.In some experiments, total and phosphorylated levels of STAT5 aremeasured. The phospho-STAT5 status of certain cell types, such as NKcells, CD8+ T cells, CD4+ T cells, and/or Treg cells, is determined bystaining for the particular cell type. In some experiments, the NK cellsare stained as CD45+CD3−CD56+, the CD8+ T cells are stained asCD45+CD3+CD8+, the CD4+ T cells are stained as CD45+CD3+CD4+CD25-, andthe Treg cells are stained as CD45+CD3+CD4+CD25+FOXP3+.

The activation of STAT5 in the mouse cell lines, such as CTLL-2 cells,following treatment with the masked IL-2 polypeptide constructs or themasked IL-15 polypeptide constructs generated in Example 1 is alsoassessed. In some experiments, some CTLL-2 cells are treated withcontrols for comparison. In some experiments, some CTLL-2 cells aretreated with aldesleukin as a control for the masked IL-2 polypeptidetreatment. In some experiments, the masked IL-2 polypeptide constructsand the masked IL-15 polypeptide constructs are tested in conditionswith and without protease cleavage (e.g., activation). In someexperiments, the CTLL-2 cells are treated for 10 minutes, 15 minutes, 20minutes, or 25 minutes, and are then fixed to preserve thephosphorylation status of proteins, such as STAT5. In some experiments,each construct, as well as aldesleukin and/or other controls, isadministered at one or more concentrations. In some experiments, totaland phosphorylated levels of STAT5 are measured.

In some studies, the levels of intracellular STAT5 activation (pSTATSsignal) induced by IL-2 was determined by the following method. Frozenhuman PBMCs were thawed in water bath and added to 39 mL pre-warmedmedia (RPMI1640 medium plus 10% FBS, 1% P/S, 1% NEA), spun andreconstitute in media at 10E6 cells/mL. Cells were plated at 5E5 perwell cells in a 96 well plate. IL-2 (e.g., rhIL-2 or an exemplaryIL-2-containing polypeptide construct) diluted in medium was added toeach well, and incubated at 37° C. for 20 min. Cells were then fix with200 ul/well Fixation buffer (eBiosciences) at 4° C., overnight. Aftercentrifugation, the fixed cells were resuspended in 200 ul cold BDPhosflow buffer and incubated at 4° C. for 30 min. After washing thecells twice, they were treated with Biolegend Human TruStain FcX (2.5 uLin 50 uL total per sample in Staining buffer) for 5 min on ice. Stainingantibodies were added; 5 ul pSTATS-APC (pY694, BD), 10 ul CD56-BV421(5.1H11, Biolegend), 10 ul CD4-PerCP/Cy5.5 (A161A1, Biolegend), and 10ul CD3-FITC (UCHT1, Biolegend) and incubated for 30 min, on ice,protected from light. Cells were washed 2 times and resuspended, andanalyzed by flow cytometry.

FIGS. 12A-12D depict the results from STAT5 activation studies, asdescribed above, using the exemplary constructs AK032, AK035, AK041, orrhIL-2 as a control. The levels of STAT5 activation (%) are shown for NKcells, CD8+ T cells, effector T cells (Teff), and regulatory T cells(Treg). The AK032 and AK035 constructs include an IL-2 polypeptidelinked to an Fc domain, and the AK041 construct includes an IL-2polypeptide linked to a CD25 domain and a CD122 domain. As shown,engineered IL-2 polypeptide constructs can, in some embodiments, reduceactivation of Treg cells while retaining or enhancing activation of CD8+T cells and NK cells.

FIGS. 13A-13C depict the results from STAT5 activation studies, asdescribed above, using the exemplary constructs AK081 and AK032. TheAK081 construct with and without prior exposure to MMP10 was tested. Anisotype control as well as a no IL-2 negative control was also tested.The levels of STAT5 activation (%) are shown for NK cells, CD8+ T cells,and CD4+ T cells. The AK032 and AK081 constructs include an IL-2polypeptide linked to an Fc domain, and the AK081 construct includes acleavable peptide in the linker connecting the IL-2 polypeptide to theFc domain. As shown, the non-masked monomeric AK081 IL-2 polypeptideconstruct stimulates STAT5 activation of PBMCs with or without proteaseactivation similarly to the non-masked dimeric AK032 IL-2 polypeptideconstruct.

FIGS. 14A-14D depict the results from STAT5 activation studies, asdescribed above, using the exemplary constructs AK081 and AK111, as wellas controls that included an rhIL-2 and anti-RSV antibody. Ano-treatment control was also tested. The AK111 construct is anexemplary masked IL-2 polypeptide construct that includes a wildtypeform of an IL-2 polypeptide (except for a C125A mutation). As shown inFIGS. 14A-14C, the masked IL-2 polypeptide construct AK111 demonstratedreduced STAT5 activation as compared to the non-masked IL-2 polypeptideconstruct AK081. FIG. 14D provides EC50 (pM) and fold-change data forthe AK081, AK111 constructs, as well as the rhIL-2 control.

FIGS. 15A-15D depict the results from STAT5 activation studies, asdescribed above, using the exemplary constructs AK167 and AK168, as wellas controls that included an rhIL-2 and anti-RSV antibody. Ano-treatment control was also tested. The AK168 construct is anexemplary masked IL-2 polypeptide construct that includes a mutant formof an IL-2 polypeptide that eliminates or reduces CD25 binding. TheAK167 construct is a parental, non-masked form of the AK168 constructthat includes the same mutant IL-2 polypeptide. As shown in FIGS.15A-15C, the non-masked AK167 construct demonstrated reduced STAT5activation as compared to the rhIL-2 control, and the masked IL-2polypeptide construct AK168 did not induce detectable STAT5 activation.FIG. 15D provides EC50 (pM) and fold-change data for the AK167, AK168constructs, as well as the rhIL-2 control. The EC50 of the AK168construct was non-detectable (n.d.).

FIGS. 16A-16D depict the results from STAT5 activation studies, asdescribed above, using the exemplary constructs AK165 and AK166, as wellas an isotype control and an IL-2-Fc control, that were (+MMP10) or werenot previously exposed to the MMP10 protease. The AK166 construct is anexemplary masked IL-2 polypeptide construct that includes a wildtypeform of an IL-2 polypeptide (except for a C125A mutation). The AK165construct is a parental, non-masked form of the AK166 construct thatincludes the same IL-2 polypeptide. The key as shown in FIG. 16A alsoapplies to FIG. 16B, and the key as shown in FIG. 16C also applies toFIG. 16D. As shown in FIGS. 16A-16D, STAT5 activation was greatlydiminished for the masked AK166 construct (without protease cleavage),but was restored to levels resembling the IL2-Fc control followingexposure to the activating protease MMP10.

FIGS. 17A-17C depict the results from STAT5 activation studies, asdescribed above, using the exemplary constructs AK109 and AK110, as wellas an isotype control and an IL-2-Fc control, that were (+MMP10) or werenot previously exposed to the MMP10 protease. The AK109 and AK110construct are exemplary masked IL-2 polypeptide constructs that includehalf-life extension domains having different heterodimerizationmutations. The key as shown in FIG. 17B also applies to FIG. 17A. Asshown in FIGS. 17A-17C, STAT5 activation was greatly diminished for themasked AK109 and AK110 construct (without protease cleavage), but wasgreatly increased to levels approaching the IL2-Fc control followingexposure to the activating protease MMP10.

FIGS. 18A-18D depict the results from STAT5 activation studies, asdescribed above, using the constructs AK211, AK235, AK253, AK306, AK310,AK314, and AK316, as well as an an rhIL-2 control. This includesconstructs that are parental, non-masked constructs (AK235, AK253,AK306, AK310, AK314) that include various mutations that modulate CD25binding. FIG. 18D provides EC50 data for each of the tested constructsas well as the rhIL-2 control.

FIGS. 19A-19D depict the results from STAT5 activation studies, asdescribed above, using the constructs AK081, AK167, AK216, AK218, AK219,AK220, and AK223 that have been activated by protease, as well as an anrhIL-2 control. A no-treatment control was also tested. This includesmasked IL-2 polypeptide constructs (AK216, AK218, AK219, AK220, andAK223) that include various mutations that modulate CD25 binding. Theconstructs were previously exposed to an activating protease prior totesting their ability to activate STAT5. FIG. 19D provides EC50 data foreach of the tested constructs as well as the rhIL-2 control.

FIGS. 20A-20C depict the results from STAT5 activation studies, asdescribed above, using the constructs AK081, AK189, AK190, and AK210, aswell as an an anti-RSV control. This includes masked IL-2 polypeptideconstructs (AK189, AK190, AK210) that include an IL-2 polypeptide havinga C125A mutation and include the same cleavable peptide sequence(RAAAVKSP; SEQ ID NO: 121) but having different linker sequences due todifferences in the amino acid residues on the N-terminus of the proteasecleavage sequence. The key as shown in FIG. 20A also applies to FIGS.20B and 20C.

FIGS. 21A-21C depict the results from STAT5 activation studies, asdescribed above, using the constructs AK167, AK191, AK192, and AK193, aswell as an an anti-RSV control. This includes masked IL-2 polypeptideconstructs (AK189, AK190, AK210) that include an IL-2 polypeptide havingR38A, F42A, Y45A, E62A, and C125A mutations and include the samecleavable peptide sequence (RAAAVKSP; SEQ ID NO: 121) but havingdifferent linker sequences due to differences in the amino acid residueson the N-terminus of the protease cleavage sequence. The key as shown inFIG. 21A also applies to FIGS. 20B and 20C.

Example 3: In Vivo Characterization of Masked IL-2 and IL-15Polypeptides

Pharmacokinetics

The pharmacokinetics of the masked IL-2 polypeptide constructs and themasked IL-15 polypeptide constructs generated in Example 1 is assessedin vivo using mouse models.

Mice are treated intravenously or subcutaneously with the constructs andthe concentration of the construct in the plasma is measured over time.In some experiments, some mice are treated with controls for comparison.In some experiments, some mice are treated with aldesleukin as a controlfor masked IL-2 polypeptide treatment. In some experiments, the micethat are treated have tumors. In some experiments, the mice that aretreated are tumor-free. In some experiments, mice are treated with theconstructs and blood is drawn at various times over the course oftreatment, which may include drawing blood prior to the initiation oftreatment and processing it to obtain plasma. In some experiments, bloodis drawn at various time points over the course of two weeks, threeweeks, or four weeks or more of treatment. In some experiments, the meanplasma concentration of the administered constructs, as well asaldesleukin and/or other controls, is measured. Masked IL-2 polypeptideconstructs are detected in the plasma samples after dilution into PBSTween with IL-2- and human Fc-specific ELISAs and are quantified using astandard curve generated for each construct. Masked IL-15 polypeptideconstructs are detected in the plasma samples after dilution into PBSTween with IL-15- and human Fc-specific ELISAs and are quantified usinga standard curve generated for each construct. The percentage of fulllength and cleaved constructs is determined by western blot withanti-huFc-HRP and anti-huIL-2-HRP and by whole mass and peptide massspectrometry.

The pharmacokinetics of the masked IL-2 polypeptide constructs and themasked IL-15 polypeptide constructs in tumors is also assessed in vivousing mouse models. Mice having tumors are treated intravenously orsubcutaneously with the constructs and the concentration of theconstruct in tumors of the mice is assessed. In some experiments, somemice are treated with controls for comparison. In some experiments, somemice are treated with aldesleukin as a control for masked IL-2polypeptide treatment. Tumors are analyzed for the presence of theconstructs as well as the presence of particular proteases. In someexperiments, the tumors are analyzed for the presence and percentage offull length and cleaved constructs.

Some pharmacokinetic studies were carried out according to the followingmethod. C57BL/6 female mice were purchased from Charles RiverLaboratories and were 8-10 weeks old at the start of study. MC38 tumorcells (5×10⁵ cells per mouse) were injected subcutaneously into theright flank of each mouse. Upon reaching ˜100 mm³ sized tumors (day 0),the mice received a single 2 mg/kg intravenous dose of the construct ofinterest (e.g., a non-masked parental IL-2 polypeptide construct, amasked IL-2 polypeptide construct, or a non-cleavable masked IL-2polypeptide construct) in PBS. Constructs tested include, for instance,AK032, AK081, AK111, AK167, AK168, AK191, AK197, AK203, AK209, andAK211. Plasma were collected at 5 min, days 1, 2 and 5 after dosing.Drug levels were determined using ELISAs utilizing anti-human IgG (cloneM1310G05, Biolegend) as the capture antibody and various detectionantibodies. HRP or biotin conjugated detection antibodies against humanIgG (ab97225, Abcam) or CD122 (clone 9A2, Ancell) and IL-2 (Poly5176,Biolegend) were utilized to detect total and non-cleaved drug levels,respectively.

FIGS. 23A-23D describe results from pharmacokinetic studies carried out,as described above, in tumor-bearing mice using the constructs AK032,AK081, AK111, AK167, and AK168, as well as an anti-RSV control. FIG. 23Aprovides a simplistic depiction of the structure of each of theconstucts tested. As indicated, AK111 and AK168 are exemplary maskedIL-2 polypeptide constructs. The AK167 and AK168 constructs includemutations (R38A, F42A, Y45A, and E62A) that eliminate or reduce bindingto CD25. FIG. 23B shows Fc levels in plasma (μg/mL) by detecting humanIgG, FIG. 23C shows Fc-CD122 levels in plasma (μg/mL) by detecting humanCD122, and FIG. 23D shows Fc-IL2 levels in plasma (μg/mL) by detectinghuman IL-2.

FIGS. 24A-24D describe results from pharmacokinetic studies carried out,as described above, in tumor-bearing mice using the constructs AK167,AK191 AK197, AK203, AK209, and AK211, as well as an anti-RSV control.FIG. 24A provides a simplistic depiction of the structure of each of theconstucts tested. As indicated, AK168, AK191, AK197, AK203, and AK209are exemplary masked IL-2 polypeptide constructs that each include adifferent cleavable peptide sequence in the linker connecting the IL-2polypeptide to the half-life extension domain. FIG. 24B shows Fc levelsin plasma (μg/mL) by detecting human IgG, FIG. 24C shows Fc-IL2 levelsin plasma (μg/mL) by detecting human IL-2, and FIG. 24D shows Fc-CD122levels in plasma (μg/mL) by detecting human CD122. As shown in FIGS.24B, 24C, and 24D, the Fc levels, Fc-IL2 levels, and Fc-CD122 levels inthe plasma are similar among the masked IL-2 polypeptide constructstested.

Bioactivity in Mice

The in vivo bioactivity of the masked IL-2 polypeptide constructs andthe masked IL-15 polypeptide constructs generated in Example 1 isassessed in vivo using mouse models, such as C57BL/6 mice. Mice aretreated with the constructs and in vivo bioactivity is assessed. In someexperiments, some mice are treated with controls for comparison. In someexperiments, some mice are treated with aldesleukin as a control formasked IL-2 polypeptide treatment. In some experiments, the mice thatare treated have tumors. In some experiments, the mice that are treatedare tumor-free. In some experiments, the dose-dependent expansion ofimmune cells is assessed in the mice. In some experiments, the mice aretreated with various doses of a construct, aldesleukin, or othercontrol. In some experiments, the mice are treated over the course oftwo weeks. Blood is collected from the mice at various time points andis then stained using antibodies to immune cell markers of interest. Insome experiments, the longitudinal kinetics of the proliferation andexpansion of certain circulating cell types, such as CD8+ T cells, NKcells, and Treg cells, is also determined, as well as the ratio of CD8+T cells and NK cells to CD4+CD25+FoxP3+Treg cells. In some experiments,the mice are assessed for vascular leakage, such as by assessing foredema and lymphocyte infiltration in certain organs like the lung andliver as determined by organ wet weight and histology.

In some studies, vascular leakage was assessed in order to assesspotential toxicity-related effects mediated by IL-2 based therapies byperforming the following method. Repeated dose toxicity studies wereconducted using C57BL/6 female mice that were purchased from CharlesRiver Laboratories and were 8-10 weeks old weighing 18-22 grams at thestart of study. Groups of 5 mice received daily intraperitonealinjections of masked and non-masked IL-2 constructs in PBS daily for 4or 5 days. The constructs tested included AK081, AK111, AK167, andAK168. A control antibody was also administered as a control. Two hoursafter the last dose, all mice received an intravenous injection of 0.1ml of 1% Evans blue (Sigma, cat# E2129) in PBS. Two hours after Evansblue administration, mice were anesthetized and perfused with 10 U/mlheparin in PBS. Spleen, lung and liver were harvested and fixed in 3 mlof 4% PFA 2 days at 4° C. prior to measuring the absorbance of thesupernatant at 650 nm with NanoDrop OneC (Thermo Fisher Scientific,Waltham, Mass.) as an indicator of vascular leak of Evans blue. Fixedorgans were embedded in paraffin, sectioned, and stained withhematoxylin and eosin. Histopathological studies and quantification werecarried out by NovoVita Histopath Laboratory, LLC. (Allston, Mass.)according to standard procedures. FIGS. 30A-30D depict results from anin vivo study as described above for assessing vascular leakage usingthe exemplary masked IL-2 polypeptide constructs AK111 and AK168, aswell as the non-masked IL-2 polypeptide constructs AK081 and AK167, andan anti-RSV control. FIG. 30A shows the percentage (%) of body weightloss, and FIGS. 30B, 30C, and 30D shows the weight in grams of theliver, lung, and spleen, respectively, for each.

Vascular leakage as indicated by measuring the extent of dye leakageinto tissues was also assessed for the AK081, AK111, AK167, and AK168constructs, along with an anti-RSV control, with results shown in FIGS.31A and 31B for the liver and lung, respectively. The extent of dyeleakage was measured based on absorbance at 650 nm.

Vascular leakage as indicated by measuring the extent of mononuclearcell perivascular invasion into the liver and lung was also assessed forthe AK081, AK111, AK167, and AK168 constructs, along with an anti-RSVcontrol, with results shown in FIGS. 32A and 32B for the liver and lung,respectively. The average number of mononuclear cells in the liver (FIG.32A) and the average number of mononuclear cells in the lung (FIG. 32B)depicted for each. As shown in FIG. 32B, for instance, the masked IL-2polypeptide constructs AK111 and AK168 did not result in a detectablenumber of mononuclear cells in the lung, unlike the non-maskedconstructs AK081 and AK167.

Infiltrating Immune Cell Phenotype

The phenotype of immune cells infiltrating tumors in vivo in mousemodels treated with the masked IL-2 polypeptide constructs or the maskedIL-15 polypeptide constructs generated in Example 1 is assessed. Miceare treated with the constructs and the phenotype of tumor-infiltratingimmune cells is assessed. In some experiments, some mice are treatedwith controls for comparison. In some experiments, some mice are treatedwith aldesleukin as a control for masked IL-2 polypeptide treatment.Mice bearing tumors are treated with a construct, aldesleukin, oranother control, and tumors, tissues such as liver, lung, and spleen,and blood, are collected at various time points following the initialdose, such as five days, seven days, or ten days after the initial dose.In some experiments, immune cells are isolated from the tumors, tissues,and blood, and are subject to phenotypic assessment using flowcytometry. In some experiments, the isolated immune cells are assessedusing markers of interest, such as those for CD8+ T cells, Memory CD8+ Tcells, activated NK cells, CD4+ T cells, and CD4+Treg cells.

In some studies, the phenotype of immune cells infiltrating tumors invivo was assessed using the following method. C57BL/6 female mice werepurchased from Charles River Laboratories and were 8-10 weeks old at thestart of study. MC38 tumor cells (5×10⁵ cells per mouse) were injectedsubcutaneously into the right flank of each mouse. Upon reaching ˜100mm³ sized tumors (day 0), the mice received a single 2 mg/kg intravenousdose of the construct of interest (e.g., a non-masked parental IL-2polypeptide construct, a masked IL-2 polypeptide construct, or anon-cleavable masked IL-2 polypeptide construct) in PBS. On day 5, micewere euthanized by CO2 asphyxiation and tumors, livers, spleens andblood were harvested. Cell suspensions were prepared from spleens bymechanical disruption and and passing through a 40 μm cell strainer. Thetumor tissues were enzymatically digested using Miltenyi TumorDissociation Kit reagents (Miltenyi cat#130-096-730) and the gentleMACSDissociator (Miltenyi) was used for the mechanical dissociation steps.Red blood cells in the spleen and tumor cell suspensions and blood werelysed using ACK buffer (Gibco cat# A10492). The cell suspensions werestained with the following antibodies: CD45 (clone 30-F11, eBioscience),CD3 (clone 2C11, Biolegend), CD8 (clone 53-6.7, BD Biosciences), CD4(clone RM-45, BD Biosciences), FOXP3 (MF-14, Biolegend), CD25 (3C7,Biolegend), CD44 (clone IM7, eBioscience), and NKp46 (29A1.4,eBioscience). Data acquisition was carried out on the MACSQuant Analyzerflow cytometer (Milenyi) and data were analyzed using the FlowJo.

Results from studies testing the in vivo responses of CD4, CD8, NK, andTreg percentages in spleen, blood, and tumor, as carried out asdescribed above, using the AK032, AK081, AK111, AK167, and AK168constructs, as well as an anti-RSV IgG control, are shown in FIGS.25A-25L. AK111 and AK168 are exemplary masked IL-2 polypeptideconstructs.

Results from studies testing the in vivo responses of CD4, CD8, NK, andTreg percentages in spleen, blood, and tumor, as carried out asdescribed above, using the AK167, AK168, AK191, AK197, AK203, AK209, andAK211 constructs, as well as an anti-RSV IgG control, are shown in FIGS.26A-26L. AK168, AK191, AK197, AK203, and AK209 are exemplary masked IL-2polypeptide constructs that each include a different cleavable peptidesequence in the linker connecting the IL-2 polypeptide to the half-lifeextension domain. Statistical analysis was performed using One-way ANOVAas compared to the non-cleavable AK211 construct.

Results from studies testing the in vivo responses of CD4, CD8, NK, andTreg percentages in spleen, blood, and tumor, as carried out asdescribed above, using the AK235, AK191, AK192, AK193, AK210, AK189,AK190, and AK211 constructs are shown in FIGS. 27A-27L. AK191, AK192,AK193, AK210, AK189, and AK190 are exemplary masked IL-2 polypeptideconstructs that each include a cleavable peptide sequence in the linkerconnecting the IL-2 polypeptide to the half-life extension domain. Thelinker sequence also differs among these constructs, depending on thelinker sequence utilized. AK189, AK190, and AK210 include an IL-2polypeptide having a C125A mutation, and AK191, AK192, and AK193 includean IL-2 polypeptide having C125A, R38A, F42A, Y45A, and E62A mutations.The AK235 construct is a non-masked construct and the AK211 constructincludes a non-cleavable linker sequence. Statistical analysis wasperformed using One-way ANOVA as compared to the non-cleavable AK211construct.

Results from studies testing the in vivo T cell activation in spleen,blood, and tumor, as carried out as described above, using the AK235,AK191, AK192, AK193, AK210, AK189, AK190, and AK211 constructs, asdescribed above, are shown in FIGS. 28A-28I. T cell activation wasmeasured as the mean fluorescence intensity (MFI) of CD25 in CD8+ Tcells, CD4+ T cells, or Foxp3+ cells in the spleen, blood, and tumor.Statistical analysis was performed using One-way ANOVA as compared tothe non-cleavable AK211 construct.

In Vivo Cleavage

The in vivo cleavage of masked cytokine constructs (e.g., masked IL-2polypeptide constructs or masked IL-15 polypeptide constructs) isassessed. In some studies, a control antibody is administered forcomparison. In some studies, in vivo cleavage is assessed byadministering the construct of interest in a mouse and, after a certainperiod of time, capturing human IgG and then measuring the levels of,e.g., human IgG, CD122, and IL-2 or IL-15.

In some studies testing the in vivo cleavage of masked IL-2 polypeptideconstructs, drug levels (i.e., levels of the administered construct,including cleavage byproducts) were determined using ELISAs utilizinganti-human IgG (clone M1310G05, Biolegend) as the capture antibody andvarious detection antibodies. HRP or biotin conjugated detectionantibodies against human IgG (ab97225, Abcam) or CD122 (clone 9A2,Ancell) and IL-2 (Poly5176, Biolegend) were utilized to detect total andnon-cleaved drug levels, respectively. The concentrations of cleaved andreleased IL-2 is calculated by subtracting non-cleaved (i.e., intact)from total drug concentrations. FIGS. 29A-29D depict the results fromstudies testing the in vivo cleavage of the exemplary masked IL-2polypeptide constructs AK168 (cleavable peptide sequence: MPYDLYHP; SEQID NO: 96) and AK209 (cleavable peptide sequence: VPLSLY; SEQ ID NO:135). The AK167 construct is a cleavable non-masked IL-2 polypeptideconstruct that includes the same IL-2 polypeptide as the masked AK168construct. As shown in FIGS. 29B-29D, both the masked (AK168 and AK209)and non-masked (AK167) constructs were effectively cleaved, and bothcleavable peptide sequences were cleaved. FIG. 29E depicts results froma pharmacokinetic study of total plasma IgG concentration (μg/mL) fortotal levels of the AK167, AK168, and AK209 constructs, and for levelsof non-cleaved forms of each construct.

Tumor Eradication and Inhibition of Metastasis

The ability of the masked IL-2 polypeptide constructs and the maskedIL-15 polypeptide constructs generated in Example 1 to promote tumoreradication and to inhibit metastasis is assessed in vivo using mousemodels, such as syngeneic MC38, CT26, and B 16F10 tumor models.

Mice are implanted with tumor cells subcutaneously, and tumors areallowed to grow to a palpable size. Tumor-bearing mice are treated withthe masked IL-2 constructs or the masked IL-15 polypeptide constructsand tumor volume is measured over the course of treatment. In someexperiments, some mice are treated with controls for comparison. In someexperiments, some mice are treated with aldesleukin as a control formasked IL-2 polypeptide treatment. Tumor volume is measured periodicallyover the course of treatment. In some experiments, body weight is alsomeasured periodically over the course of treatment. In some experiments,plasma samples are produced over the course of the treatment andanalyzed for pharmacokinetics, pharmacodynamics, cleavage, and bloodmarkers, such as those for CD8+ T cells, Memory CD8+ T cells, activatedNK cells, CD4+ T cells, and CD4+Treg cells.

The capability of the masked IL-2 polypeptide constructs and the maskedIL-15 polypeptide constructs to inhibit metastasis is also assessed invivo using mouse models suitable for metastasis studies, such assyngeneic CT26 tumor models for assessing lung metastasis. Mice areimplanted with tumor cells subcutaneously. In some experiments, tumorsare allowed to grow to a palpable size prior to treatment. In someexperiments, treatment begins before tumors grow to palpable size.Tumor-bearing mice are treated with the masked IL-2 constructs or themasked IL-15 polypeptide constructs and are assessed for tumor cellmetastasis into tissues such as lungs, liver, and lymph nodes.

In some studies, a syngeneic tumor model was used to assess the abilityof masked IL-2 polypeptide constructs to reduce tumor volume inaccordance with the following method. C57BL/6 female mice were purchasedfrom Charles River Laboratories and were 8-10 weeks old at the start ofstudy. MC38 tumor cells (5×105 cells per mouse) were injectedsubcutaneously into the right flank of each mouse. Upon reaching ˜125mm3 sized tumors (day 0), the mice were randomized to receive 2 mg/kgdoses of AK081, AK111, AK167, or AK168, or an anti-RSV antibody as acontrol, in PBS. Mice were dosed intraperitoneally, three times a weekfor 6 doses. Tumor volume was calculated (Length*(Width{circumflex over( )}2)/2) using dial calipers and body weights were recorded twiceweekly. FIGS. 33A and 33B show results from a syngeneic tumor modelstudy that assessed tumor volume and body weight over the course oftreatment. As shown in FIG. 33A, treatment using exemplary IL-2polypeptide constructs, including the masked constructs AK111 and AK168,resulted in tumor growth inhibition over time as compared to theanti-RSV control. As shown in FIG. 33B, there was a general lack of bodyweight reduction observed when the mice were treated with the maskedconstructs AK111 and AK168.

Bioactivity in Cynomolgus Monkeys

The in vivo bioactivity of the masked IL-2 polypeptide constructs andthe masked IL-15 polypeptide constructs generated in Example 1 isassessed in vivo in cynomolgus monkeys. Cynomolgus monkeys are treatedwith the constructs and in vivo bioactivity, pharmacokinetics, andcleavage is assessed. In some experiments, some monkeys are treated withcontrols for comparison. In some experiments, some monkeys are treatedwith aldesleukin as a control for masked IL-2 polypeptide treatment. Insome experiments, the monkeys are treated with various doses of theconstruct, aldesluekin, or other control. Blood is collected from themonkeys at various time points and is then evaluated for certain celltypes, such as CD8+ T cells, Memory CD8+ T cells, activated NK cells,CD4+ T cells, and CD4+Treg cells, and/or markers of interest, such asfor the dose-response of total lymphocytes, Ki67+, and of soluble CD25.In some experiments, the longitudinal kinetics of the proliferation andexpansion of certain circulating T and NK cell types is assessed. Insome experiments, pharmacokinetics and cleavage of the masked IL-2polypeptide constructs and the masked IL-15 polypeptide constructs aredetermined by ELISA, PAGE, and mass spectrometry.

To test the safety profile of exemplary masked IL-2 polypeptideconstructs in non-human primates, a dose ranging study is performed inaccordance with the following method. Groups of 3 healthy malecynomolgus monkeys (Macaca fascicularis) are randomly assigned toreceive a single intravenous bolus dose of 2 mL/kg of activatable (i.e.,cleavable) masked IL-2 polypeptide proteins or non-cleavable masked IL-2polypeptide proteins at 10, 30 and 100 nmol/kg in 100 mM sodium citratebuffer (pH 5.5). A third group receives the parental non-masked,cleavable protein at 3, 10 and 30 nmol/kg as a positive control. Thisthird group is dosed at a lower range to account for higher potency ofthe parental non-masked molecules. Doses are calculated in moles toaccount for differences in molecular weight. Blood samples are collectedbefore dosing and 1, 24, 48, 72, 96, 168, 264 and 336 hours post-dosing.An automated hematology analyzer is used to monitor changes inlymphocyte subsets and serum chemistry. Total and intact (i.e.,non-cleaved) drug levels are measured from plasma using custom ELISA asdescribed above. Soluble CD25 levels are measured with an ELISA (R&Dsystems, cat# DR2A00) to monitor immune stimulation. Plasma levels ofinflammatory cytokines are quantified using custom multiplexedelectrochemiluminescence assay (Meso Scale Discovery). Blood pressure ismonitored as an indicator of vascular leak syndrome. PK is analyzedusing an ELISA that captures IL-2 and detects human Fc and by an ELISAthat captures human Fc and detects human Fc.

The present invention is not intended to be limited in scope to theparticular disclosed embodiments, which are provided, for example, toillustrate various aspects of the invention. Various modifications tothe compositions and methods described will become apparent from thedescription and teachings herein. Such variations may be practicedwithout departing from the true scope and spirit of the disclosure andare intended to fall within the scope of the present disclosure.

IX. SEQUENCES SEQ ID AMINO ACID SEQUENCE 1APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 2APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 3APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETIVEFLNRWI TFAQSIISTLT4 APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTKKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 5APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFAFAMPKKATELKHLQCLEEELKPLEEVLNGAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 6APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHPDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 7APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTKKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 8APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTAKFAMPKKATELKHLQCLEEELKPLEEVLNGAQSKNFHPDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 9ELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQOEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICT 10AVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYE FQVRVKPLQ11 GGSSPPMPYDLYHPSGP 12 GSPMPYDLYHP 13 GSPPMPYDLYHPSGP 14GSPSMPYDLYHPSGP 15 GPPSGSSPMPYDLYHPSGGG 16 GSSGGPPGGMPYDLYHPSGGG 17SGSPSGSGGGMPYDLYHPSGGG 18 GPPGPPGSSGMPYDLYHPSGGG 19GSSSGPPGPPSMPYDLYHPSGGG 20 PA 21 GGGGSGGGGSGGGGS 22 PSGPSAGGAA 23GGPPASAGS 24 GSPPAGGAP 25 GPSGSGGAA 26 GGGGSGGGGS 27GGGGSGGGGSGGGGSGGGGS 28 PGSGS 29 GGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG 30GGGGSGGGGSGGGGSGGGGSGGGGS 31 GGGGSGGGGSGGGGSGGGGSGGGGSGGGGS 32GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS 33GGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGS 34 GGSSPP 35 SGP 36 GSP 37 GSPP38 GSPS 39 GPPSGSSP 40 GSSGGPPGG 41 SGSPSGSGGG 42 GPPGPPGSSG 43 SGGG 44GSSSGPPGPPS 45 GGS 46 GGGSSGGS 47 GGSGG 48 GGGS 49 GS 50 GSGGGSSGGS 51GSSGGS 52 GGGSSGGSG 53 GGSAGGS 54 GHS 55 GPS 56 GAS 57 SGG 58 SGGSGG 59SSG 60 GGGSGG 61 GG 62 GGG 63 SHGG 64 HGGG 65 SGAA 66 SGPA 67 GGSGGS 68GGSGGP 69 GGSGGG 70 GSGGPGPS 71 SGPPGSS 72 SSGGSGP 73 SSPSPSGG 74 SPGGSS75 GGPGSSP 76 SGPPGGPSS 77 GPGPGSPPGGSS 78 SGPP 79 PGSPSSS 80 PSPGGPS 81GGPPS 82 PSPPS 83 SGGPGP 84 GPSPGS 85 GSPGPSP 86 PSSGGSS 87 SGSSGP 88GGSSSPP 89 GSPGSP 90 PPPS 91 APPPS 92 AAPPPS 93 SAPPPS 94 SSGP 95 SSPGP96 MPYDLYHP 97 GGIGQLTA 98 DLGRFQTF 99 DSGGFMLT 100 TSVLMAAP 101TSEFVFAPDQ 102 KLVLPVLP 103 KPILFFRL 104 ANQLKG 105 QSQLKE 106 HEQLTV107 PANLVAPDP 108 PAPGVYPGP 109 APAGLIVPYN 110 PQALVA 111 VGNLNF 112VANLLYE 113 VYNLMD 114 TFNIKQ 115 DLWKLLP 116 PGSTKRA 117 QQYRALKS 118YVPRAVL 119 GVNKWPT 120 LAQAVRSS 121 RAAAVKSP 122 DLLAVVAAS 123 VQTVTWPD124 AIPMSIPP 125 GYEVHHQK 126 VHHQKLVF 127 IRRVSYSF 128 MPYDLYHPILFFRL129 GGIGQLTSVLMAAP 130 DSGGFMLTLVLPVLP 131 TSEFVFAPDLGRFQTF 132TSTSGRSANPR 133 TSTSGRSANPG 134 TSTSGRSANPH 135 VPLSLY 136 TSASGASASAA137 PSSPGGGSSP 138 ISSGLLSGRSDNH 139 ISSGLLSGRSDDH 140 ISSGLLSGRSDIH 141ISSGLLSGRSDQH 142 ISSGLLSGRSDTH 143 ISSGLLSGRSANP 144 ISSGLLSGRSDNP 145ISSGLLSGRSANPRG 146 AVGLLAPPGGLSGRSDNH 147 AVGLLAPPGGLSGRSDDH 148AVGLLAPPGGLSGRSDIH 149 AVGLLAPPGGLSGRSDQH 150 AVGLLAPPGGLSGRSDTH 151AVGLLAPPGGLSGRSANP 152 AVGLLAPPGGLSGRSDNP 153 AVGLLAPPSGRSANPRG 154DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 155DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 156DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 157EIVLTQSPDFQSVTPKFKVTITCSANSALSYMYWYQQKPDQSPKLWVHGTSNLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCHHWSNTQWTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC 158QVQLVQSGAEVKKPGSSVKVSCKASGYTFTNYFMNWVRQAPGQGLEWMGRVDPEQGRADYAEKFKKRVTITADKSTSTAYMELSSLRSEDTAVYYCARRAMDYNYGFAYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPDVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPEEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 159MYRMQLLSCIALSLALVTNSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWTITFCQSIISTLT 160APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 161 CGGHQYERRGGC 162 CSGHQYERREGC 163 CGGHYFERHGGC 164CSGHYFERHEGC 165 CSFHQYERHEGC 166MRISKPHLRSISIQCYLCLLLNSHFLTEAGIHVFILGCFSAGLPKTEANWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTS 167NWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTS 168ASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQWNVFSCSVMHEALHNHYTQKSLSLSPGK 169DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 170TVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC 171DAHKSEVAHRFKDLGEENFKALVLIAFAQYLQQCPFEDHVKLVNEVTEFAKTCVADESAENCDKSLHTLFGDKLCTVATLRETYGEMADCCAKQFPERNECFLQHKDDNPNLPRLVRPEVDVMCTAFHDNEETFLKKYLYEIARRHPYFYAPFLLFFAKRYKAAFTECCQAADKAACLLPKLDELRDEGKASSAKQGLKCASLQKFGERAFKAW AVARLSQRFPKAEFAEVSKLVTDLTKVHTECCHGDLLECADDRADLAKYICENQDSISSKLKECCEKPLLEKSHCIAEVENDEMPADLPSLAADFVGSKDVCKNYAEAKDVFLGMFLYEYA RRHPDYSVVLLLRLAKTYETTLEKCCAAADPHECYAKVFDEFKPLVEEPQNLIKQNCELFEQLGEYKFQNALLVRYTKKVPQVSTPTLVEVSRNLGKVGSKCCKHPEAKRMPCAEDCLSV FLNQLCVLHEKTPVSDRVTKCCTESLVNGRPCFSALEVDETYVPKEFNAETFTFHADICTLSEKERQIKKQTALVELVKHKPKATKEQLKAVMDDFAAFVEKCCKADDKETCFAEEGKK LV AASQAALGL172 LAEAKVLANRELDKYGVSDYYKNLINNAKTVEGVKALIDEILAALP 173 DICLPRWGCLW 174RLIEDICLPRWGCLWEDD 175 DCAWHLGELVWCT 176 NKFRGKYK 177 NARKFYKG 178FYWHCLDE 179 FYCHWALE 180 FYCHTIDE 181AQQNAFYQVLNMPNLNADQRNGFIQSLKDDPSQSANVLGEAQKLNDSQAPK 182ADAQQNKFNKDQQSAFYEILNMPNLNEEQRNGFIQSLKDDPSQSTNVLGEAKKLNESQA PK 183ADNNFNKEQQNAFYEILNMPNLNEEQRNGFIQSLKDDPSQSANLLAEAKKLNESQAPK 184ADNKFNKEQQNAFYEILHLPNLNEEQRNGFIQSLKDDPSQSANLLAEAKKLNDAQAPK 185ADNKFNKEQQNAFYEILHLPNLTEEQRNGFIQSLKDDPSVSKEILAEAKKLNDAQAPK 186VDNKFNKEQQNAFYEILHLPNLNEEQRNAFIQSLKDDPSQSANLLAEAKKLNDAQAPK 187QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKORFTISRDNSKNTLYLQMNSLRAEDTAVYYCAREDWLGEADYGMDVWGQG TTVTVSS 188DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQATQFPTFGQGTKVEIKR 189QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDGEQWRGFDYWGQGTTV TVSS 190DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQATQFPTFGQGTKVEIKR 191QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVTRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDQEQWRLAFDYWGQGTT VTVSS 192DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQATQFPTFGQGTKVEIKR 193QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGAVAGTGRDYYYYGMDV WGQGTTVTVSS194 DIVMTQSPLSLPVTPGEPASISCRSSQSLLHSNGYNYLDWYLQKPGQSPQLLIYLGSNRASGVPDRFSGSGSGTDFTLKLISRVEAEDVGVYYCMQALQTPLTFGGGTKVEIKR 195QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGSYYDSSGYYYGEDFDYW GQGTTVTVSS196 DIVMTQTPLLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQTSQFPTFGQGTKVEIKR 197QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFITSRDNSKNTLYLQMNSLRAEDTAVYYCAREEWELEDYGMDVWGGQGT TVTVSS 198DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQTTQFPTFGQGTKVEIKR 199QVQLVESGGGVVQPGRSLRLSCAASGFTFSSYGMHWVRQAPGKGLEWVAVIWYDGSNKYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAREDFDSHYGMDVWGQGTTV TVSS 200DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQTTQFPTFGQGTKVEIKR 201QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDNWGSDAFDIWGQGTTVT VSS 202DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQVTQFPTFGQGTKVEIKR 203QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDDWFGEADYGMDVWGQG TTVTVSS 204DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQTTQFPTFGQGTKVEIKR 205QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARRISITPFDYWGQGTTVTVSS 206EIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSPLTFGGGTKVEIKR 207EVQLVQSGAEVKKPGESLKISCKGSGYSFTSYWIGWVRQMPGKGLEWMGIIYPGDSDTRYSPSFQGQVTISADKSISTAYLQWSSLKASDTAMYYCARQQVAGMLDYWGQGTTVTVSS 208EIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQAPRLLIYGASSRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSPLTFGGGTKVEIKR 209QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARDDFWSDYPFDYWGQGTTV TVSS 210DIVMTQTPLSSPVTLGQPASISCIRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYGMQTTQFPTFGQGTKVEIKR 211QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCAREEWFGEADYGMDVWGQG TTVTVSS 212DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQTTQFPTFGQGTKVEIKR 213QVQLVESGGGVVQPGRSLRLSCAASGFYFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTITSRDNSKNTLYLQMNSLRAEDTAVYYCARGAVAGTGRDYYYYGMDV WGQGTTVTVSS214 DIVMTQSPLSLPVTPGEPASISCRSSQSLLHSNGYNYLDWYLQKPGQSPQLLIYLGSNRASGVPDRFSGSGSGTDFTLKLISRVEAEDVGVYYCMQALQTPLTFGGGTKVEIKR 215QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGSYYDSSGYYFGEDFDYW GQGTTVTVSS216 DIVMTQTPLSSPVTLGQPASISCRSSQSLVHSDGNTYLSWLQQRPGQPPRLLIYKISNRFSGVPDRFSGSGAGTDFTLKISRVEAEDVGVYYCMQVTQFPTFGQGTKVEIKR 217QVQLVESGGGVVQPGRSLRLSCAASGFTFSIYGMHWVRQAPGKGLEWVTVIWYDGSNEYYADSVKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCARGTVAGTGRDYYYYGMDV WGQGTTVTVSS218 DIVMTQSPLSLPVTPGEPASISCRSSQSLLHSNGYNYLDWYLQKPGQSPQLLIYLGSNRASGVPDRFSGSGSGTDFTLKLISRVEAEDVGVYYCMQALQTPLTFGGGTKVEIKR 219EIVLTQSPGTLSLSPGERATLSCRASQSVSSSYLAWYQQKPGQAPRLLIYGASRATGIPDRFSGSGSGTDFTLTISRLEPEDFAVYYCQQYGSSHTFGQGTKLEISR 220EVQLVQSGAEVKKPGESLKISCKGSGYSFTSYWIGWVRQMPGKGLEWMGIIYPGDSDTRYSPSFQGQVTISADKSISTAYLQWSSLKASDTAMYYCARGGNWNCFDYWGQGTLVTVSS 221GMLSLAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYPERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQAFRTLTGH 222 QKLTTVDI 223 CQKLTTVDIC 224 SHYFER 225CSHYFERC 226 AVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGARDSQKLTTVDIVTLRVLCREGVRWRVMAIQDF 227LNITILTPNGNEDTTADFFLTTMPTDSLSVSTLPLPEVQCFVFNVEYMNCTWNSSSEPQPTNLTLHYWYKNSDNDKVQKCSHYLFSEEITSGCQLQKKEIHLYQTFVVQLQDPREPRRQATQMLKLQNLVIPWAPENLTLHKLSESQLELNWNNRFLN HCLEHLVQYRTDWDHSWTEQSVDYRHKFSLPSVDGQKRYTFRVRSRFNPLCGSAQHWSEW SHPIHWGSNTSKENPFLFALEAV 228TLPLPEVQCFVFNVEYMNCTWNSSSEPQPTNLTLHYWYKNSDNDKVQKCSHYLFSEEITSGCQLQKKEIHLYQTFVVQLQDPREPRRQATQMLKLQNLVIPWAPENLTLHKLSESQLELNWNNRFLNHCLEHLVQYRTDWDHSWTEQSVDYRHKFSLPSVDGQKRYTFRVRSRFNPLCGSAQHWSEWSHPIHWGSNT 229TLPLPEVQCFVFNVEYMNCTWNSSSEPQPTNLTLHYWYKNSDNDKVQKCSHYLFSEEITSGCQLQKKEIHLYQTFVVQLQDPREPRRQATQMLKLQNLVI 230SSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFC QSIISTLT231 ELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGEMETSQFPGEEKPQASPEGRPESETSCLVTTTDFQIQTEMAATMETS 232ITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPP 233ITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPS LKCIRDP 234ITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPS LKCIR 235SGGSGGGGSGGGSGGGGSLQ 236 SGRSA 237 SGRSANA 238 SGRNAQ 239 SGRNAQVR 240SGRSDN 241 SGRSDNPN 242 GSGKSA 243APASSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 244APASSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 245APASSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAWSIISTLT 246APASSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTKKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 247APASSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFAFAMPKKATELKHLQCLEEELKPLEEVLNGAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 248APASSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAWSIISTLT 249APASSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTKKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 250APASSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTAKFAMPKKATELKHLQCLEEELKPLEEVLNGAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 251APASSSTKKTQLQLEHLLLDLQMILNGINNIKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETIVEFLNRWI TFCQSIISTLT252 EVQLVESGGGLVQPGGSLRLSCAASGFTFRSFGMSWVRQAPGKEPEWVSSISGSGSDTLYADSVKGRFTISRDNAKTTLYLQMNSLKPEDTAVYYCTIGGSLRSSQGTQVTVSS 253EVQLVESGGGLVQPGGSLRLSCAASGFTFSSFGMSWVRQPGKEPEWVSSISGSGSDTLYADSVKGRFTISRDNAKTTLYLQMNSLKPEDTAVYYCTIGGSLSRSSQGTQVTVSS 254EVQLVESGGGLVQPGGSLRLSCAASGFTFRSFGMSWVRQAPGKGLEWVSSISGSGSDTLYADSVKGRFTISRDNAKTTLYLQMNSLKPEDTAVYYCTIGGSLSRSSQGTQVTVSS 255EVQLVESGGGLVQPGNSLRLSCAASGFTFRSFGMSWVRQAPGKGLEWVSSISGSGSDTLYADSVKGRFTISRDNAKTTLYLQMNSLKPEDTAVYYCTIGGSLSRSSQGTLVTVSS 256EVQLVESGGGLVQPGNSLRLSCAASGFTFRSFGMSWVRQAPGKGLEWVSSISGSGSDTLYADSVKGRFTISRDNAKTTLYLQMNSLRPEDTAVYYCTIGGSLSRSSQGTLVTVSS 257EVQLVNESGGGLVQPGNSLRLSCAASGFTFSSFGMSWVRQAPGKGLEWVSSISGSGSDTLYADSVKGRETISRDNAKTTLYLQMNSLRPEDTAVYYCTIGGSLSRSSQGTLVTVSS 258EVQLVESGGGLVQPGNSLRLSCAASGFTFSSFGMSWVRQAPGKGLEWVSSISGSGSDTLYADSVKGRETISRDNAKNTLYLQMNSLRPEDTAVYYCTIGGSLSRSSQGTLVTVSS 259EVQLVESGGGLVQPGNSLRLSCAASGFTFSSFGMSWVRQAPGKGLEWSSISGSGSDTLYADSVKGRFTISRDNAKNTLYLQMNSLRPEDTAVYYCTIGGSLSRSGQGTLVTVSS 260TSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 261AVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 262 GSGPDSGGFMLTSGPAP 263GSSPPGDSGGFMLTSGP 264 DSGGFMLTS 265DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 266DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSGPDSGGFMLTSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 267DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVFWESNGQPENNYKTTPPVLDFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 268 GSGP 269 GPAP 270 ISSGLLGGLSGRSDQP 271ISSGLLSGRSDQG 272 ISSGLLSGRSDQA 273 ISSGLLSGRSDSP 274 ISSGLLSGRSDTP 275ISSGLLSGRSDMP 276 ISSGLLSGRSD 277 ISSGLLSGRSDQP 278 ISSGLLGGLSGRSDNP 279ISSGLLSSGGLSGRSDQP 280 ISSGLLSSGGLSGRSDNP 281 ISSGLLSGRS 282ISSGLLSGRSESP 283 ISSGLLSGRSEQP 284 ISSGLLSGRSEQH 285 LSSGLLSGRSDQP 286LSSGLLGGSGRSDQP 287 LSSGLLSGRSDQG 288 LSSGLLSGRSDQA 289 LSSGLLSGRSDSP290 LSSGLLSGRSDTP 291 LSSGLLSGRSDMP 292 LSSGLLSGRSD 293GKQLRVVNEYSSMDNMLLG 294 LSSGLLGGLSGRSDNP 295 LSSGLLSSGGLSGRSDQP 296LSSGLLSSGGLSGRSDNP 297 GKQLRVVNEYSSEDNMLLG 298 LSSGLLSGRSESP 299LSSGLLSGRSEQP 300 LSSGLLSGRSEQH 301 MPYDLYH 302 LSGRSDNH 303 GGGSSP 304SGGP 305 SGPSGSPG 306 GSIPVSLRSG 307 GPSGPAGLKGAPG 308 GPPGPAGMKGLPG 309GYVADAPK 310 KKLADEPE 311 GGSRPAHLRDSGK 312 SFTQARVVGG 313VHMPLGFLGPRQARVVN 314 LSGRSDNHSPLGLAGS 315 VPLSLYSG 316 IPESLRAG 317IPVSLRSG 318 SGSGGSPVPLSLYSGQP 319 GGGSSPVPLSLYSGGP 320GGSSPPVPLSLYSGPSGSPG 321 GGSGGGSGGGSGGGSGGGSG 322GGSGGGSGGGSGGGSGGGSGGGSG 323 PGPGP 324 SGCCGGHQYERRGGC 325SGGCSGHQYERREGC 326 SGGCGGHYFERHGGC 327 SGGCSGHYFERHEGC 328SGGCSFHQYERHEGC 329 PSGSS 330 GSPG 331 GGSPGG 332 GGPGGP 333 GGSG 334GSPPGG 335 GPGSPG 336 GSSPPG 337 GGP 338 SGPGSGS 339 GGSSPPGGGSSGGGSGP340 SGPGSGS 341 SGSGGSP 342 IYDQKT 343 AHNYKT 344 MMDQAN 345 MLGEFVSE346 GLVALRGA 347 KEHKYKAE 348 GGSSPPGGGSSGGGSGPGSGS 349GGSSPPVPLSLYSGPGSGS 350 GNPMGSEPVNFKQLKVVNGGP 351 GNPMGSEPVNFKLLRVVNGGP352 GNPMGSDPVFNKQLRVVNGGP 353 GNPMGSDPVNFKLLRVVNGGP 354GGSSPPMPYDLYHPSGPSGSPG 355 GGSSPPGGGSSGGGSGPSGSPG 356 RQARVVG 357LGGSGRSNAQVRLE 358 LGGSGRKASLSLE 359 SGRIGFLRTA 360 SGAIGFLRTA 361RPARSGRSAGGSVA 362 VTGRGDSPASS 363 PRFKIIGG 364 LSGRIGFLRTA 365LSGRSNAMPYDLYHP 366 LSGRSNAGGIGQLTA 367 LSGRSNAVPLSLY 368LSGRSNADSGGFMLT 369 LSGRSNAHEQLTA 370 LSGRSNARAAAVKSP 371LSGRSNATSVLMAAP 372 VPLSLYLSGRSNA 373 DSGGFMLTLSGRSNA 374GGIGQLTALSGRSNA 375 MPYDLYHPLSGRSNA 376 HEQLTVLSGRSNA 377RAAAVKSPLSGRSNA 378 TSVLMAAPLSGRSNA 379 IPVSLRSGRSNAQRLE 380VPLSLYRQARVVG 381 DSGGFMLTRQARVVG 382 GGIGQLTARQARVVG 383MPYDLYHPRQARVVG 384 HEQLTVRQARVVG 385 RAAAVKSPRQARVVG 386TSVLMAAPRQARVVG 387 KQLRVVNEYSSMDNMLLG 388 KQLRVVNEYSSEDNMLLG 389KQLRVVNGYSSEDNMLLG 390 KQLRVVGGLVHLKNTMET 391 TRDRLDEVNFKQLRVVNG 392TRDRLDEVNFKLLRVVNG 393 TRDRLDPVNFKQLRVVNG 394 TRDRLDPVNFKLLRVVNG 395NPMGSEPVNFKQLRVVNG 396 NPMGSEPVNFKLLRVVNG 397 NPMGSDPVNFKQLRVVNG 398NPMGSDPVNFKLLRVVNG 399 TYSRSKYLATA 400 TYSRSYLATA 401 KQLRVVNEYSSE 402KQLRVVNGYSSE 403 KQLRVVGGLVAL 404 KQLRVVNGLVAL 405 SPGRVVGGLVAL 406PQPRTYSRSRYL 407 PQPRTTSRSRYL 408 VVNEYSSSRGPYH 409 VVNEYSSERGPYH 410NKVSMSSSRGPYH 411 NKVSMSSTRGPYH 412 APAMMRGSVILTV 413 APAMMEGSVILTV 414RGSVIITVQTVTW 415 RGSVILTVQTVTW 416 GTRDRLDEVNFKQLRVVNGGP 417GTRDRLDEVNFKLLRVVNGGP 418 GTRDRLDPVNFKQLRVVNGGP 419GTRDRLDPVNFKLLRVVNGGP 420 RKGKALAAYRLE 421 RKGKAGAAYRLE 421 RQARVVGGLVAL423 GGVRGPRFKIIGG 424 GGVRGPRVKIIGG 425 VTGRGDSHSLTTN 426 VTGRGDSPSLTTN427 TGHGQASQGLLDR 428 TGHGQASSGLLDR 429 KQLRVVNENLENY 430 KQLRVVNGNLENY431 SNVNDVANYNFF 432 SNVNDVSNYNFF 433 IDFNAAQNLYEK 434 IDFNAAYNLYEK 435IQWNAGQPLQER 436 IQWNAPQPLQER 437 SMDNRLLGLFGE 438 SMDNMLLGLFGE 439VPIDDPQDLLEG 440 VPIDDPEDLLEG 441 IPENLPPGLPLT 442 IPENLPPLLPLT 443QPPSLTKNQVSL 444 QPPSLTRNQVSL 445 DSHSLTKNQVSL 446 DSHSLTTNQVSL 447KAIQLTKNQVSL 448 KAIQLTYNQVSL 449 AEPWTNRNTDGS 450 AEPWTVRNTDGS 451KQLRVVNG 452 KQLRVVTGRGDSP 453 KQLRVVNGRGDSP 454 PSSRRRVVRKGVS 455PSSRRRVNRKGVS 456 SPGRVVTGRGDSP 457 SPGRVVGGRGDSP 458 NSGRAVTGRGDSP 459NSGRAVTYRGDSP 460 TGHGQPSSRRRVN 461 TGHGQASSRRRVN 462 TGHGQSSSRGPYH 463TGHGQASSRGPYH 464 RGSVILTKNQVSL 465 RGSVILTTNQVSL 466 SPGRVVGINYWLA 467SPGRVVGGNYWLA 468 SPGRVVGSNKGAI 469 SPGRVVGGNKGAI 470 PGARGRAPNHAVV 471PGARGRAFNHAVV 472 PGARGNAFNNLDR 473 PGARGRAFNNLDR 474 VSNKYISNNEQLP 475VSNKYFSNNEQLP 476 KVSNKALHVTNI 477 KVSNKALPVTNI 478 VTGRGPSPDVPLT 479VTGRGDSPDVPLT 480 TGHGQRSSNIRTS 481 TGHGQASSNIRTS 482 TGHGQHSSNIANI 483TGHGQASSNIANI 484 TGHGQASRNDYSY 485 TGHGQASSNDYSY 486 KALHVTNRNTDGS 487KALHVTNINTDGS 488 RVVRKKVSNKALP 489 RVVRKGVSNKALP 490 RQARVVGINYWLA 491RQARVVGGNYWLA 492 GKQLRVVNGYSSEDNMLLGGP 493 GKQLRVVGGLVHLKNTMETGP 494AGQPKQLRVVNG 495 AGQPLQLRVVNG 496 AGQPLQERVVNG 497 AGQPKQERVVNG 498GTANKQLRNVNG 499 GTANKQLHVVNG 500 GTANIQLRVVNG 501 GTANIQLHVYNG 502GKQLRVVNEYSSMDNMLLGGP 503 GKQLRVVNEYSSEDNMLLGGP 504 KQLRTVAGLAGK 505KQLRTVNGLAGK 506 KQLRVVAGLAGK 507 KQLRVVNGLAGK 508 GIKYKQLRVVNG 509GIKYKYLRVVNG 510 GIKYLQLRVVNG 511 GIKYLYLRVVNG 512 THLDLTYSRSKYLATA 513THLDLTPSRSKYLATA 514 THLDLTYSRSRYLATA 515 THLDLTPSRSRYLATA 516TYSRSKYLAPANGNAE 517 TYSRSKYLATANGNAE 518 TYSRSRYLAPANGNAE 519TYSRSRYLATANGNAE 520 DPVNFKQLRYVNEYSSE 521 DPVNFKQLRVVNGYSSE 522DPVNFKKLRVVNEYSSE 523 DPVNFKKLRVVNGYSSE 524 RKGKAGAAKNLNEKDY 525RKGKAGAAKNLYEKDY 526 RKGKAGAAQNLNEKDY 527 RKGKGAAQNLYEKDY 528VTGRGDSHSLTKNQVSL 529 VTGRGDSHSLTTNQVSL 530 VTGRGDSPSLTKNQVSL 531VTGRGDSPSLTTNQVSL 532 TGHGQASSERSSNIRTS 533 TGHGQASSERSSNSRTS 534TGHGQASSERSSTIRTS 535 TGHGQASSERSSTSRTS 536 GISSGLLSGRSDQPSGP 537GGSGISSGLLSGRSDQPSGP 538 DPVNFKLLRVVNEYSSE 539 DPVNFKLLRVVNGYSSE 540DPVNFKQLRVVGGLVAL 541 DPVNFKQLRVVNGLVAL 542 DPVNFKLLRVVGGLVAL 543DPVNFKLLRVVNGLVAL 544 KQLRVQNGDSTE 545 KQLRVVNNDATE 546 KQLRVVNGDSTE 547ISNNKQLRVVNG 548 ISNNKQLPVVNG 549 ISNNEQLRVVNG 550 ISNNEQLPVVNG 551KVSNKQLRVVNG 552 KVSNKQLPVVNG 553 KVSNKALRVVNG 554 KVSNKALPVVNG 555KQLRVQNNDATE 556DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 557DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQVASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAYEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETIVEFLNRWITFAQSIISTLT 558APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGGGGSGGGGSGGGGSELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVFWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSP G 559DKTHTCPPCPAPELLGGPSVFLFPPKPKDTIMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 560DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTKKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 561DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFAFAMPKKATELKHLQCLEEELKPLEEVLNGAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 562APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTTMCEYADETATIVEFLNRWITFAQSIISILTPSGPSAGGAAEIVLTQSPDFQSVTPKEKVTITCSANSALSYMYWYQQKPDQSPKLWVHGTSNLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCHHWSNTQWTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC 563ELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNYYKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGPPASAGSQVQLVQSGAEVKKPGSSVKVSCKASGYTFTNYFMNWVRQAPGQGLEWMGRVDPEQGRADYAEKFKKRVTITADKSTSTAYMELSSLRSEDTAVYYCARRAMDNYGFAYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPDVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALTAPEEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 564ELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGSPPAGGAPQVQLVQSGAEVKKPGSSVKVSCKASGYTFTNYFMNWVRQAPGQGLEWMGRVDPEQGRADYAEKFKKRVTITADKSISTAYMELSSLRSEDTAVYYCARRAMDNYGFAYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSCDKTHTCPPCPAPELLGGPDVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPEEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 565APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPGSGSGGAAEIVLTQSPDFQSVTPKEKVTITCSANSALSYMYWYQQKPDQSPKLWVHGTSNLASGVPSRFSGSGSGTDFTLTINSLEAEDAATYYCHHWSNTQWTFGGGTKVEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC 566DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRNWITFAQSIISTLTGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLTVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 567DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAPTSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLEFLTPDTQYEFQVRVKPLQ 568DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 569DKTHTCPPCPAPELLGGPSVFLFPPKPKDTL0MISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTKKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 570DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKA.KGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTAKFAMPKKATELKHLQCLEEELKPLEEVLNGAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 571DKTHTCPPCPAPELLGGPSVFLFPPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGSGGGGSGGGGSGGGGSGGGGSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 572DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 573DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 574DKTHTCPPCPAPELLGGPSVFLFPPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWTIFAQSIISTLT 575DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 576DKTHTCPPCPAPELLGGPSVFLFRPKPKDTLMISRTPEVTCVVVDVSHEDPFVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGSGGGGSGGGGSGGGGSGGGGSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 577DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSILSILT 578DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 579DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSGGGGSAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 580APTSSSTKKTQLQLEHELLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATEIKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGGGGSGGGCSELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 581APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGGGGSGGGGSGGGGSGGGGSELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFTRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYNDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKARGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKS LSLSPG 582APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGGGGSGGGGSGGGGSELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNWQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSL SPG 583APTSSSTKKTQLQLEHELLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGGGGSGGGGSELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 584APTSSSTRKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVFLNRWITFAQSIISTLTGGGGSGGGGSGGGGSGGGGSELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTDKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQ KSLSLSPG 585DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSGGPPGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 586DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKENWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTSGSPSGSGGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 587DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVENAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMEEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPGPPGSSGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 588DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDLAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSSGPPGPPSMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 589DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVIKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFELYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSGGPPGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 590DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTSGSPSGSGGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLIPDTQYEFQVRVKPLQ 591DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNHFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPGPPGSSGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 592DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSSGPPGPPSMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 593DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVFWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLKDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTETGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEIQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 594DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPFVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHELLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSGGPPGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 595DKTHTCPPCPAPELLGGPSVFLFPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHITQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVIEFLNRWITFAQSIISTLTSGSPSGSGGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLAMPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 596DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYYDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPGPPGSSGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 597DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSSGPPGPPSMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 598DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQPQLICTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSGGPPGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 599DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTSGSPSGSGGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 600DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPGPPGSSGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 601DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPAELCDDDPPEIPHATFKAMAYKEGTMLNCECKRGFRRIKSGSLYMLCTGNSSHSSWDNQCQCTSSATRNTTKQVTPQPEEQKERKTTEMQSPMQPVDQASLPGHCREPPPWENEATERIYHFVVGQMVYYQCVQGYRALHRGPAESVCKMTHGKTRWTQPQLICTGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSSGPPGPPSMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 602DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPSGSSPMPYDLYHPSGGGCAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 603DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQEPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPL Q 604DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDTAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPMPYDLYHPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISILT 605DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 606DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPSMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 607DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 608DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 609DKTHTCPPCPAPELLGGPSVFLFPPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGSAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCTQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVK PLQ 610DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDF 611DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWVYDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSGGPPGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDF 612DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPPVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGDFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTSGSPSGSGGGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDF 613DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPGPPGSSGMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDF 614DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSEFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGSSSGPPGPPSMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNILITGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDF 615DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 616DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 617DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 618DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLTCLVEGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQESLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 619DKTHTCPPCPAPELLSGPSVFLFPPKPKDTLMISRTPEVVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 620DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRVRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 621DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYDTTPPVLDSDGSFFLVSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 622DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 623DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 624DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVEGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQESLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 625DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTYPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK 626DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLWCINKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGGAVNGTSQTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQ 627DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTPGPGPMPYDLYHPSGGCGGHQYERRGGC 628DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSISPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMACEYADETATIVEFLNRWITFAQSIISTLTPGPGPMPYDLYHPSGGCSGHQYERREGC 629DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPENKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKKTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTPGPGPMPYDLYHPSGGCGGHYFERHGGC 630DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGWENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLIPGPGPMPYDLYHPSGCCSGHYFERHEGC 631DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTPGPGPMPYDLYHPSGGCSFHQYERHEGC 632DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTPSGSSMPYDLYHPSGGCGGHQYERRGGC 633DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDCFSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTPSGSSMPYDLYHPSGGCSGHQYERREGC 634DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTPSGSSMPYDLYHPSGGCGGHYFERHGGC 635DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTPSGSSMPYDLYHPSGGCSGHYFERHEGC 636DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTPSGSSMPYDLYHPSGGCSFHQYERHEGC 637DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGSAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTFWSPWSQPLAFRTKPAALGKD 638DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 639DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLTCLVKGFYRSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 640DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKELTKNQVSLWCLNKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 641DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 642DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLTGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 643DKTHTCPPCPAPELLGGPSVFLFRPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVNINVFVLELKGSETTFMCEYADETATIVEFLNRWTTFAQSIISTLTGPPSGSSPMPYDLYHPSGGGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 644DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGSAVNGTSQETCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEFAPLLTLKQKQEWICLETLTPDTQYEFQVRVK PLQ 645DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILCLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 646DKTHTCPPCPAPELLGGPSVFLPPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDCSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 647DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNRYTQKSLSLSPGAPTSSSTKKTQLQLEILCLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 648DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 649DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALYNNEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLCLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 650DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 651DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSKDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILLLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLLSNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 652DKTHTCPPCPAPELLGGPSVFLFPPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSEFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 653DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVFWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 654DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLCLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 655DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSKDELTKNQVSLTCLKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISILT 656DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEHLLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 657DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALFINHYTQKSLSLSPGAPTSSSTKKTQLQLEILCLLLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 658DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILLLLLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFTQSIISTLT 659DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILLLLLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 660DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIANEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMEEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILCLFLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 661DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSPGAPTSSSTKKTQLQLEILLLFLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 662DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPSRDELTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGAPTSSSTKKTQLQLEILLLFLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 663DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMSRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNOQPENNYDTTPPVLDSDGSFFLVSDLTVDKSRWQQGNVPSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 664DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLPGPGSGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 665DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYTDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVEGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQESLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 666DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISEQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 667DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 668 GGSSPPMPYDLYHPSGPGSGS 669DKTHTCPPCPAPELLGGPSVFLFPPKPKDTIMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHFDPRDVVSNINVFVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 670DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRWDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 671DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMITSRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFVPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSKWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTAVSPWSQPLAFFRTKPAALGKD 672DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGISSGLLSGRSDNHSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 673DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSKWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGAVGLLAPPGGLSGRSDNHSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNKWITFAQSIISTLT 674DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEVKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 675DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALIPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 676DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSPGGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPKDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 677DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPRAAAVKSPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 678DKTHTCPPCPAPELLGGPSVFLPPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEYHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSGSVMHEALHNHYTQKSLSLSPGGGPGGPRAAAVKSPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 679DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSGSVMHEALHNHYTQKSLSLSPGGGSGRAAAVKSPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVINLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 680DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSKWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPRAAAVKSPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 681DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGPGGPRAAAVKSPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 682DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSGHEQLTVSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 683DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPHEQLTVSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 684DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPPGGHEQLTVSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 685DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSGHEQLTVSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVIEFLNRWITFAQSIISTLT 686DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPHEQLTVSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 687DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHTTQKSLSLSPGGSPPGGHEQLTVSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 688DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSGPDSGGFMLTSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLITKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 689DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPGSPGDSGGFMLTSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 690DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSSPPGDSGGFMLTSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 691 GISSGLLSGRSDNHGGP 692DKTHTCPPCPAPELLSGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPGSPGDSGGFMLTSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 693DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSSPPGDSGGFMLTSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 694DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGISSGLLSGRSDNHSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 695DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGAVGLLAPPGGLSGRSDNHSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLERALKPLEEVLNLAQSKNFHLRPRDLISNINNIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 696DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSPGGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 697DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEFALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 698DKTHTCPPCPAPELLGGPSVFLFPPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSGRAAAVKSPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 699DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPGGGSSGGGSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWTIFAQSIISTLT 700DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSGSVMHEALHNHYTQKSLSLSPGGGSSPPGGGSSGGGSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 701DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEERLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 702DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVENAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTEKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEELNRWITFAQSIISTILT 703DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFNMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 704DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDSNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 705DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTAKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 706DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFRMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 707DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTITPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFAFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 708DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPRVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHRSGPAPTSSSTKKTQLQLEHLELDLQMILNGINNYKNPKLTRMLTFKFAMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 709DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVTDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVTVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 710DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTGMLTFKFAMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 711DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 712DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 713DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGISSGLLSGRSDNHGGPAPTSSSTKKTQLQLEHLLLDLQMILNCGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 714DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGISSGLLSGRSDNHGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 715DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPGSGSWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTS 716DKTHTCPPCPAPELLSGPSVFLFPFKPKDTLMISTRPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGPPSGSSPMPYDLYHPSGGGAVNGTSQTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 717DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEERLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWIFFAQSIISTLT 718DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKA.KGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTEKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 719DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFNCSVMHEALTHHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 720DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTAKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 721DKTHTCPPCPAPELLSGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLTCLVEGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQESLSLSPG 722DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFRMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 723DKTHTCPPCPAPELLSGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALIPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWIEFAQSIISTLT 724 GISSGLLSGRSDNPSGP 725 GGSGISSGLLSGRSDNPSGP 726DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGSPGVPLSLYSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTAMLTAKFAMPKKATELKHLQCLEEALKPLEEVLNLAQSKNFHLRPRDLISNINVINLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 727 SGS 728DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNTKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSGRAAAVKSPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 729DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGISSGLLSGRSSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 730DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSGISSGLLSGRSSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVENLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITITAQIISTLT 731DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGISSGLLSGRSDNPSGPAPTSSSTKKTQLQLEHLLLDLQMLINGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 732DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSGISSGLLSGRSDNPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLEKGSETTFMCEYADETATIVEFLNRWITFAQSIISILT 733DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGISSGLLSGRSDQPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWTIFAQSIISTLT 734DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSGISSGLLSGRSDQPSGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 735DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGKQLRVVNEYSSMDNMLLGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 736DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPFNTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGKQLRVVNEYSSEDNMLLGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 737DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGKQLRVVNGYSSEDNMLLGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWFIFAQSIISTLT 738DKTHTCPPCPAPELLGGPSVFLFPPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGKQLRVVGGLVHLKNTMETGPAPTSSSTKKTQLQLEHLKLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 739DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQWDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLNKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGTRDRLDEVNFKQLRVVNGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 740DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLNKGFYPSDLAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGTRDRLDEVNFKLLRVVNGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 741DKTFHCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGTRDRLDPVNFKQLRVVNGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 742DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTESKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGTRDRLDPVNFKLLRVVNGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 743DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLLSPGGNPMGSEPVNFKQLRVVNGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 744DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGNPMGSEPVNFKLLRVVNGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 745DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGNPMGSDPVNFKQLRVVNGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 746DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGNPMGSDPVNFKLLRVVNGGPAPTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 747DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPSGSPGNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSEKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINT S 748DKTHCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKAEPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPGGGSSGGGSGPSGSPGNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINT S 749DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPSGSPGNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTSGGGGSGGGGSGGGGSGGGGSITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPAASSPSSNNTAATTAAIVPGSQLMPSKSPSTGTTEISSHESSHGTPSQTTAKNWELTASASHQPPGVYPQGHSDTT 750DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPSGSPGNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTSGGGGSGGGGSGGGGSGGGGSITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPA AS 751DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPGGGSSGGGSGPGSGSNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFHIVQMFINTS 752DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPGSGSNWVNVISDLKKIEDLIQSMHHIDATLYTESDVHPSCKTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFYHIVQMFINTSGGGGSGGGGSGGGGSGGGGSITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPAASSPSSNNTAATTAAIVPGSQLMPSKSPSTGTTEISSHESSHGTPSQTTAKNWELTASASHQPPGVYPQGHSDTT 753DKTHTCPPCPAPELLGGPSVFLPPMPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALIPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVFWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPMPYDLYHPSGPGSGSNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTSGGGGSGGGGSGGGGSGGGGSITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPAA S 754DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREFQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPVPLSLYSGPGSGSNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFQSFVHIVQMFINTS 755DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGSAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWFDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKDPGGPSPVFLSLYSGGPITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSGGGGSGGGGSGGGGSGGGGSNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTS 756DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGSAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENERLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKDSGSGGSPVPLSLYSGGPITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSGGGGSGGGGSGGGGSGGGGSNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTS 757DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGFGSGSAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRCNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWICLETLTPDTQYEFQVRVKPLQGEFTTWSFWSQPLAFRTKPAALGKDGGGSSPVPLSLYSGGPITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSGGGGSGGGGSGGGGSGGGGSSNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLFLQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTS 758DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPVPLSLYSGPSGSPGNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTSGGSGGGSGGGSGGGSGGGSGITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPAASSPSSNNTAATTAAIVPGSQLMPSKSPSTGTTEISSHESSHGTPSQTTAKNWELTASASHQPPGVYPQGHSDTT 759DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWENGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPVPLSLYSGPSGSPGNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTSGGSGGGSGGGSGGGSGOTSGGGSGITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVENKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPAASSPSSNNTAATTAAIVPGSQLMPSKSPSTGTTEISSHESSHGTPSQTTAKNWELTASASHQPPGVYPQGHSDTT 760DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPVPLSLYSGPGSGSNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTSGGGGSGGGGSGGGGSGGGGSGGGGSITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKE PAAS 761DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRDELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGGGSSPPVPLSLYSGPGSGSNWVNVISDLKKIEDLIQSMHIDATLYTESDVHPSCKVTAMKCFLLELQVISLESGDASIHDTVENLIILANNSLSSNGNVTESGCKECEELEEKNIKEFLQSFVHIVQMFINTSGGGGSGGGGSGGGGSGGGGSGGGGSITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPAASSPSSNNTAATTAAIVPGSQLMPSKSPSTGTTEISSHESSHGTPSQTTAKNWELTASASHQPPGVYPQGHSDTT 762 PGPGPMPYDLYHPSGGCGGHQYERRGGC 763PGPGPMPYDLYHPSGGCSGHQYERREGC 764 PGPGPMPYDLYHPSGGCGGHYFERHGGC 765PGPGPMPYDLYHPSGGCSGHYFERHEGC 766 PGPGPMPYDLYHPSGGCSFHQYERHEGC 767PSGSSMPYDLYHPSGGCGGHQYERRGGC 768 PSGSSMPYDLYHPSGGCSGHQYERREGC 769PSGSSMPYDLYHPSGGCGGHYFERHGGC 770 PSGSSMPYDLYHPSGGCSGHYFERHEGC 771PSGSSMPYDLYHPSGGCSFHQYERHEGC 772DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 773DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHINAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKELTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLKSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 774DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVYTLPPCRKKLTKNQVSLWCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 775APTSSSTKKTQLQLEILCLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 776APTSSSTKKTQLQLEILLLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 777APTSSSTKKTQLQLEILCLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 778APTSSSTKKTQLQLEILLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 779APTSSSTKKTQLQLEHLCLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 780APTSSSTKKTQLQLEHLLLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 781APTSSSTKKTQLQLEILLLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 782APTSSSTKKTQLQLEILLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 783APTSSSTKKTQLQLEHLLLLLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 784APTSSSTKKTQLQLEHLCLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVENLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 785APTSSSTKKTQLQLEHLLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 786APTSSSTKKTQLQLEHLLLFLQMILNGILNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 787APTSSSTKKTQLQLEILCLLLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 788APTSSSTKKTQLQLEILLLLLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 789APTSSSTKKTQLQLEILLLLLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 790APTSSSTKKTQLQLEILCLFLQMILNGINNYKNPKLTRMLTFKTYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFCQSIISTLT 791APTSSSTKKTQLQLEILLLFLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFIQSIISTLT 792APTSSSTKKTQLQLEILLLFLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 793DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKAEPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYDTTPPVLDSDGSFFLVSDLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPG 794 SG 795 PGSG 796DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVEGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQESLSLSPG 797 GISSGLLSGRSSGP 798GGSGISSGLLSGRSSGP 799 GSG 800 GISSGLLSGRSDNHSGP 801GGAVGLLAPPGGLSGRSDNHSGP 802 GSPGVPLSLYSGP 803 GGSSPPVPLSLYSGP 804GGSPGGVPLSLYSGP 805 GGSSPPRAAAVKSPSGP 806 GGPGGRAAAVKSPSGP 807GGSGRAAAVKSPSGP 808 GGSGHEQLTVSGP 809 GGSSPPHEQLTVSGP 810GSPPGGHEQLTVSGP 811 GSGPDSGGFMLTSGP 812 GPGSPGDSGGFMLTSGP 813APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTSKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 814APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTGMLTFKFAMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 815APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEERLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 816APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTEKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 817APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFNMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 818APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFYMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 819APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTAKFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 820APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFRMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 821APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFAFYMPKKATELKHLQCLEEELKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 822APTSSSTKKTQLQLEHLLLDLQMILNGINNYKNPKLTRMLTFKFAMPKKATELKHLQCLEESLKPLEEVLNLAQSKNFHLRPRDLISNINVIVLELKGSETTFMCEYADETATIVEFLNRWITFAQSIISTLT 823ITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPAASSPSSNNTAATTAAIVPGSQLMPSKSPSTGTTEISSHESSHGTPSQTTAKNWELTASASHQPPGVYQGHSDTT 824ITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPSTVTTAGVTPQPESLSPSGKEPAAS 825ITCPPPMSVEHADIWVKSYSLYSRERYICNSGFKRKAGTSSLTECVLNKATNVAHWTTPSLKCIRDPALVHQRPAPPS 826AVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRSNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWISLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 827AVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRSNISWEISQASHYFEDHLEFEARTLSPGHTWEEAPLLTLKWKQEWISLATLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 828DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGSAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENERLMAPISLQVVHVETHRSNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWISLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 829DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGSAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQPFKPFENLRLMAPISILQVVHVETHRSNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWISLATLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD 830DKTHTCPPCPAPELLGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYASTYRVVSVLTVLHQDWLNGKEYKCKVSNKALPAPIEKTISKAKGQPREPQVCTLPPSRDELTKNQVSLSCAVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLVSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGPGSGSAVNGTSQFTCFYNSRANISCVWSQDGALQDTSCQVHAWPDRRRWNQTCELLPVSQASWACNLILGAPDSQKLTTVDIVTLRVLCREGVRWRVMAIQDFKPFENLRLMAPISLQVVHVETHRSNISWEISQASHYFERHLEFEARTLSPGHTWEEAPLLTLKQKQEWISLETLTPDTQYEFQVRVKPLQGEFTTWSPWSQPLAFRTKPAALGKD

What is claimed is:
 1. A masked cytokine comprising: a) a maskingmoiety; and b) a cytokine or functional fragment thereof, wherein themasking moiety is linked to the cytokine or functional fragment thereofvia a first linker.
 2. A masked cytokine comprising: a) a first maskingmoiety; b) a cytokine or functional fragment thereof, wherein the firstmasking moiety is linked to the cytokine or functional fragment thereofvia a first linker; and c) a second masking moiety, wherein the secondmasking moiety is linked to the cytokine or functional fragment thereofvia a second linker.
 3. A masked cytokine comprising: a) a firsthalf-life extension domain and a second half-life extension domain; b) amasking moiety; and c) a cytokine or functional fragment thereof,wherein the masking moiety is linked to the first half-life extensiondomain, wherein the cytokine or functional fragment thereof is linked tothe second half-life extension domain, and wherein the first half-lifeextension domain and the second half-life extension domain containmodifications promoting the association of the first and the secondhalf-life extension domain.
 4. A masked cytokine comprising: a) a firsthalf-life extension domain and a second half-life extension domain; b) afirst masking moiety and a second masking moiety; and c) a cytokine orfunctional fragment thereof, wherein the first masking moiety is linkedto the first half-life extension domain, wherein the second maskingmoiety is linked to the cytokine or functional fragment thereof, whereineither the second masking moiety or the cytokine or functional fragmentthereof is linked to the second half-life extension domain, and whereinthe first half-life extension domain and the second half-life extensiondomain contain modifications promoting the association of the first andthe second half-life extension domain.
 5. The masked cytokine of claim1, further comprising a half-life extension domain that is linked toeither the masking moiety or the cytokine or functional fragmentthereof.
 6. The masked cytokine of claim 2, further comprising ahalf-life extension domain that is linked to either the first maskingmoiety or the second masking moiety.
 7. The masked cytokine of claim 3,wherein the masking moiety is linked to the first half-life extensiondomain via a first linker; and/or wherein the cytokine or functionalfragment thereof is linked to the second half-life extension domain viaa second linker.
 8. The masked cytokine of claim 4, wherein: a) thefirst masking moiety is linked to the first half-life extension domainvia a first linker; and/or b) either the second masking moiety or thecytokine or functional fragment thereof is linked to the secondhalf-life extension domain via a second linker.
 9. The masked cytokineof any one of claims 1-8, wherein the cytokine or functional fragmentthereof is an IL-2 polypeptide or functional fragment thereof.
 10. Themasked cytokine of claim 9, wherein the IL-2 polypeptide or functionalfragment thereof comprises: a) an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 1-8, 160, 230, 243-251, 260, 775-792,and 813-822; or b) an amino acid sequence produced by introducing one ormore of the following amino acid substitutions into any one of SEQ IDNOs: 1-8, 160, 243-251, 260, 775-792, and 813-822: H16I, L18C, D20A,D20L, D20F, N29L, R38A, F42A, F42K, F42E, F43A, Y45A, Y45N, Y45R, E62A,E62R, E62S, L72G, L80F, R81D, L85V, I86V, I92F, and C125S.
 11. Themasked cytokine of any one of claims 1, 3, 5, 7, 9, and 10, wherein themasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 9, 10, 161-165, 187-218, 221-229, 231, and261.
 12. The masked cytokine of any one of claims 2, 4, 6, and 8-10,wherein the first masking moiety comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 9, 10, 161-165,187-218, 221-229, 231, and 261, and the second masking moiety comprisesan amino acid sequence selected from the group consisting of SEQ ID NOs:9, 10, 161-165, 187-218, 221-229, 231, and 261, and wherein the aminoacid sequence of the first masking moiety and the second masking moietyare different.
 13. The masked cytokine of any one of claims 1-8, whereinthe cytokine or functional fragment thereof is an IL-15 polypeptide orfunctional fragment thereof.
 14. The masked cytokine of claim 13,wherein the IL-15 polypeptide or functional fragment thereof comprisesthe amino acid sequence of SEQ ID NO:
 167. 15. The masked cytokine ofany one of claims 1, 3, 5, 7, 13, and 14, wherein the masking moietycomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 10, 161-165, 219-229, 232-234, 261, and 823-825.
 16. Themasked cytokine of any one of claims 2, 4, 6, 8, 13, and 14, wherein: a)the first masking moiety comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 232-234, and 823-825, and the secondmasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 219-229, and 261; b) the firstmasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 10, 161-165, 219-229, and 261, and the secondmasking moiety comprises an amino acid sequence selected from the groupconsisting of SEQ ID NOs: 232-234, and 823-825; c) the first maskingmoiety comprises an amino acid sequence produced by introducing one ormore of the following amino acid substitutions into the amino acidsequence of any one of SEQ ID NOs: 232-234, and 823-825: R24A, R26A,K34A, 540A, L42A, and P67A, and the second masking moiety comprises anamino acid sequence selected from the group consisting of SEQ ID NOs:10, 161-165, 219-229, and 261; or d) the first masking moiety comprisesan amino acid sequence selected from the group consisting of SEQ ID NOs:10, 161-165, 219-229, and 261, and the second masking moiety comprisesan amino acid sequence produced by introducing one or more of thefollowing amino acid substitutions into the amino acid sequence of anyone of SEQ ID NOs: 232-234, and 823-825: R24A, R26A, K34A, S40A, L42A,and P67A.
 17. The masked cytokine of any one of claims 5, 6, and 9-16,wherein the half-life extension domain is an antibody or fragmentthereof.
 18. The masked cytokine of claim 17, wherein the antibody orfragment thereof is a Fragment crystallizable domain (Fc domain) orfragment thereof.
 19. The masked cytokine of claim 18, wherein the Fcdomain or fragment thereof comprises the amino acid sequence of SEQ IDNO:
 154. 20. The masked cytokine of any one of claims 3, 4, and 7-19,wherein the first half-life extension domain is a first antibody orfragment thereof, and the second half-life extension domain is a secondantibody or fragment thereof.
 21. The masked cytokine of claim 20,wherein the first antibody or fragment thereof is a first Fc domain orfragment thereof, and second antibody or fragment thereof is a second Fcdomain or fragment thereof.
 22. The masked cytokine of claim 21,wherein: a) the first Fc domain or fragment thereof comprises the aminoacid sequence of SEQ ID NO: 155, and the second Fc domain or fragmentthereof comprises the amino acid sequence of SEQ ID NO: 156; b) thefirst Fc domain or fragment thereof comprises the amino acid sequence ofSEQ ID NO: 156, and the second Fc domain or fragment thereof comprisesthe amino acid sequence of SEQ ID NO: 155; c) the first Fc domain orfragment thereof comprises the amino acid sequence of SEQ ID NO: 154,and the second Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 154; d) the first Fc domain or fragment thereofcomprises the amino acid sequence of SEQ ID NO: 265, and the second Fcdomain or fragment thereof comprises the amino acid sequence of SEQ IDNO: 156; e) the first Fc domain or fragment thereof comprises the aminoacid sequence of SEQ ID NO: 156, and the second Fc domain or fragmentthereof comprises the amino acid sequence of SEQ ID NO: 265; f) thefirst Fc domain or fragment thereof comprises the amino acid sequence ofSEQ ID NO: 155, and the second Fc domain or fragment thereof comprisesthe amino acid sequence of SEQ ID NO: 616; g) the first Fc domain orfragment thereof comprises the amino acid sequence of SEQ ID NO: 616,and the second Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 155; h) the first Fc domain or fragment thereofcomprises the amino acid sequence of SEQ ID NO: 157, and the second Fcdomain or fragment thereof comprises the amino acid sequence of SEQ IDNO: 158; i) the first Fc domain or fragment thereof comprises the aminoacid sequence of SEQ ID NO: 158, and the second Fc domain or fragmentthereof comprises the amino acid sequence of SEQ ID NO: 157; j) thefirst Fc domain or fragment thereof comprises the amino acid sequence ofSEQ ID NO: 796, and the second Fc domain or fragment thereof comprisesthe amino acid sequence of SEQ ID NO: 774; k) the first Fc domain orfragment thereof comprises the amino acid sequence of SEQ ID NO: 774,and the second Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 796; l) the first Fc domain or fragment thereofcomprises the amino acid sequence of SEQ ID NO: 721, and the second Fcdomain or fragment thereof comprises the amino acid sequence of SEQ IDNO: 619; m) the first Fc domain or fragment thereof comprises the aminoacid sequence of SEQ ID NO: 619, and the second Fc domain or fragmentthereof comprises the amino acid sequence of SEQ ID NO: 721; n) thefirst Fc domain or fragment thereof comprises the amino acid sequence ofSEQ ID NO: 721, and the second Fc domain or fragment thereof comprisesthe amino acid sequence of SEQ ID NO: 772; o) the first Fc domain orfragment thereof comprises the amino acid sequence of SEQ ID NO: 772,and the second Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 721; p) the first Fc domain or fragment thereofcomprises the amino acid sequence of SEQ ID NO: 793, and the second Fcdomain or fragment thereof comprises the amino acid sequence of SEQ IDNO: 622; q) the first Fc domain or fragment thereof comprises the aminoacid sequence of SEQ ID NO: 622, and the second Fc domain or fragmentthereof comprises the amino acid sequence of SEQ ID NO: 793; r) thefirst Fc domain or fragment thereof comprises the amino acid sequence ofSEQ ID NO: 793, and the second Fc domain or fragment thereof comprisesthe amino acid sequence of SEQ ID NO: 773; s) the first Fc domain orfragment thereof comprises the amino acid sequence of SEQ ID NO: 773,and the second Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 793; t) the first Fc domain or fragment thereofcomprises the amino acid sequence of SEQ ID NO: 796, and the second Fcdomain or fragment thereof comprises the amino acid sequence of SEQ IDNO: 625; u) the first Fc domain or fragment thereof comprises the aminoacid sequence of SEQ ID NO: 625, and the second Fc domain or fragmentthereof comprises the amino acid sequence of SEQ ID NO: 796; v) thefirst Fc domain or fragment thereof comprises the amino acid sequence ofSEQ ID NO: 156, and the second Fc domain or fragment thereof comprisesthe amino acid sequence of SEQ ID NO: 156; w) the first Fc domain orfragment thereof comprises the amino acid sequence of SEQ ID NO: 796,and the second Fc domain or fragment thereof comprises the amino acidsequence of SEQ ID NO: 625; or x) the first Fc domain or fragmentthereof comprises the amino acid sequence of SEQ ID NO: 625, and thesecond Fc domain or fragment thereof comprises the amino acid sequenceof SEQ ID NO:
 796. 23. The masked cytokine of any one of claims 1, 5,and 9-22, wherein the first linker comprises a first cleavable peptide.24. The masked cytokine of claim 23, wherein the first cleavable peptidecomprises an amino acid sequence selected from the group consisting ofSEQ ID NOs: 96-153, 236-242, 264, 270-302, 306-317, 342-347, 356-415,420-491, 494-501, 504-535, and 538-555.
 25. The masked cytokine of anyone of claims 1, 5, and 9-24, wherein the first linker comprises anamino acid sequence selected from the group consisting of SEQ ID NOs:11-153, 235-242, 262-264, 268-320, 323-338, 340-354, 356-555, 668, 691,724, 725, 727, 762-771, 794, and 797-812.
 26. The masked cytokine of anyone of claims 2 and 7-22, wherein the first linker comprises a firstcleavable peptide, and/or the second linker comprises a second cleavablepeptide.
 27. The masked cytokine of claim 26, wherein the firstcleavable peptide comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302, 306-317,342-347, 356-415, 420-491, 494-501, 504-535, and 538-555, and/or thesecond cleavable peptide comprises an amino acid sequence selected fromthe group consisting of SEQ ID NOs: 96-153, 236-242, 264, 270-302,306-317, 342-347, 356-415, 420-491, 494-501, 504-535, and 538-555. 28.The masked cytokine of any one of claims 2, 7-22, 26, and 27, whereinthe first linker comprises an amino acid sequence selected from thegroup consisting of SEQ ID NOs: 11-153, 235-242, 262-264, 268-320,323-338, 340-354, 356-555, 668, 691, 724, 725, 727, 762-771, 794, and797-812, and/or the second linker comprises an amino acid sequenceselected from the group consisting of SEQ ID NOs: 11-153, 235-242,262-264, 268-320, 323-338, 340-354, 356-555, 668, 691, 724, 725, 727,762-771, 794, and 797-812.
 29. A nucleic acid encoding the maskedcytokine of any one of claims 1-28.
 30. A vector comprising the nucleicacid of claim
 29. 31. A host cell comprising the nucleic acid of claim29.
 32. A method of producing a masked cytokine comprising culturing thehost cell of claim 31 under a condition that produces the maskedcytokine.
 33. A composition comprising the masked cytokine of any one ofclaims 1-28.
 34. A pharmaceutical composition comprising the maskedcytokine of any one of claims 1-28, and a pharmaceutically acceptablecarrier.
 35. A kit comprising the masked cytokine of any one of claims1-28, or the composition of claim 33, or the pharmaceutical compositionof claim
 34. 36. A method of treating or preventing a neoplastic diseasein a subject, the method comprising administering to the subject aneffective amount of the masked cytokine of any one of claims 1-28, orthe composition of claim 33, or the pharmaceutical composition of claim34.
 37. A method of treating or preventing an inflammatory or autoimmunedisease in a subject, the method comprising administering to the subjectan effective amount of the masked cytokine of any one of claims 1-28, orthe composition of claim 33, or the pharmaceutical composition of claim34.